EP3721501A1 - Microwave component and associated manufacturing process - Google Patents

Abstract

This microwave component (10) comprises a waveguide (12) comprising an upper layer, a lower layer, and a central layer (18) intermediate between the upper layer and the lower layer, said layers defining a zone (19) of propagation of an electromagnetic wave, the propagation zone (19) extending along a propagation axis, and comprising a cavity (32) bounded by the upper layer, the lower layer, and, laterally, by two opposite lateral edges (36) of the central layer (18). The waveguide (12) comprises at least one dielectric strip (28) placed in the propagation zone (19), the dielectric strip (28) being defined in one of the upper layer and the lower layer or being placed in the cavity (32) away from the lateral edges (36) of the cavity (32).

Description

 Microwave component and method of manufacturing the same

The present invention relates to a microwave component comprising a waveguide comprising at least one upper layer having at least one electrically conductive surface, a lower layer having at least one electrically conductive surface, and a central layer interposed between the upper layer and the lower layer, said layers defining a propagation zone of an electromagnetic wave, the propagation zone extending along an axis of propagation, and comprising a cavity, the cavity being delimited by the upper layer, by the layer; lower, and, laterally, by two opposite lateral edges of the central layer.

 At present, an important problem of the telecom industry, especially for 5G base stations, the millimeter radar industry for drones, autonomous cars and more generally any type of robot, is to reduce losses in systems drastically, at a time when energy saving is essential for the applications of tomorrow. These loss levels are indeed prohibitive for equipment such as equipment upstream of a transmitting and receiving antenna (RF front-end type equipment).

 To reduce losses, it is known to design passive electronic structures by using the waveguide technology incorporated into the hollow substrate filled with air or empty (AFSIW or ESIW in English). The passive structure then forms a microwave transmission line.

 However, for some applications, the bandwidth offered by such structures is not entirely satisfactory.

 An object of the invention is therefore to manufacture and provide, at low cost, a microwave component adapted to operate in the field of millimeter wavelengths, the component having a good bandwidth and being low losses.

 To this end, the subject of the invention is a microwave component of the aforementioned type, characterized in that the waveguide comprises at least one dielectric bar arranged in the propagation zone, the dielectric bar being delimited in one of the upper layer and the lower layer or being disposed in the cavity away from the lateral edges of the cavity.

The component according to the invention may comprise one or more of the following characteristics, taken separately or in any technically possible combination: - The dielectric bar extends in a longitudinal direction parallel to the axis of propagation, and is centered on a median plane of the two lateral edges or is offset laterally of the median plane of the two side edges;

 said dielectric bar is disposed in the cavity away from the side edges of the cavity, the waveguide comprising a functional fastening component, the functional fastening component being formed by a plurality of dielectric fasteners from material with the dielectric bar, each dielectric fastener extending from one of the side edges, the dielectric fasteners being configured to perform a filter function for an electromagnetic wave propagating in the propagation zone;

 each dielectric fastener has a straight bar shape and extends from one of the lateral edges;

 said dielectric bar is disposed in the cavity away from the lateral edges of the cavity, the central layer comprising at least one dielectric underlayer, the cavity being delimited along the axis of propagation between a front end and a rear end; the core layer, the dielectric bar extending from the front end to the rear end and integral with said dielectric underlayer of the core layer;

 said dielectric bar is disposed in the cavity away from the lateral edges of the cavity, said dielectric bar being a first dielectric bar, the waveguide further comprising a second dielectric bar, the second dielectric bar being disposed in the dielectric bar; cavity, away from said first dielectric bar, and away from the side edges of the cavity;

 - The dielectric bar is defined in one of the upper layer and the lower layer, said dielectric bar having a surface defining the cavity;

 said dielectric bar is a first dielectric bar, the waveguide further comprising a second dielectric bar disposed in the propagation zone, the second dielectric bar being delimited in one of the upper layer and the lower layer, the deviation of the first dielectric bar, and having a surface defining the cavity;

 - The waveguide further comprises another dielectric bar, said other dielectric bar being disposed in the cavity, away from the side edges of the cavity;

the dielectric bar is formed in a dielectric underlayer of one of the upper layer and the lower layer, and is delimited by a portion of an electrically conductive sub-layer of said layer and laterally between two lateral boundaries; ; and the cavity is filled with a fluid having a dielectric constant, or defines a sealed closed volume and is empty of fluid.

 The invention also relates to a method of manufacturing a microwave component comprising the following steps:

 providing an upper layer and a lower layer respectively having at least one electrically conductive surface;

 providing a core layer having one or a plurality of recesses, said recess or plurality of recesses being for forming a cavity delimited laterally by opposite side edges formed by the core layer; then,

 assembling the layers so that the central layer is interposed between the upper layer and the lower layer, the layers defining a propagation zone of an electromagnetic wave, the propagation zone extending along an axis of propagation. and comprising a cavity, the cavity being formed by said recess or said plurality of recesses being delimited by the top layer, the bottom layer, and laterally by said side edges of the core layer;

 the step of providing at least one of the layers comprising the production of a dielectric bar, said dielectric bar being arranged or intended to be arranged in said layer, so that after the assembly step, the bar dielectric is disposed in the propagation zone and is delimited in one of the upper layer and the lower layer, or so that after the assembly step, the dielectric bar is disposed in the propagation zone and in the cavity away from the side edges of the cavity.

 The manufacturing method according to the invention may comprise one or more of the following characteristics, taken separately or in any technically possible combination:

 the step of supplying the central layer comprises the production of the dielectric bar, said dielectric bar being arranged or intended to be disposed in said central layer, so that after the assembly step, the dielectric bar is disposed in the propagation zone and in the cavity away from the lateral edges of the cavity, the dielectric bar being intended to be disposed between a plane defined by an upper surface of the central layer and a plane defined by a lower surface of the central layer;

the step of providing the central layer comprises: ^* Providing an initial layer, the initial layer being intended to form the core layer, comprising at least one initial dielectric sublayer and being free of recess,

^* cutting, in the initial layer, said plurality of recesses for forming the cavity,

 the step of producing the dielectric bar being implemented during the cutting of said plurality of recesses, said plurality of cutout recesses delimiting said dielectric bar, the dielectric bar having a length, taken along the axis of propagation, equal along the length of the cavity, taken along the axis of propagation;

 the step of providing the central layer comprises:

^* Providing an initial layer, the initial layer being intended to form the core layer, comprising at least one initial dielectric sublayer and being free of recess,

^* cutting, in the initial layer, said plurality of recesses for forming the cavity,

 the step of producing the dielectric bar being implemented during the cutting of said plurality of recesses, said plurality of cut-out recesses being intended to define the cavity, and delimiting the dielectric bar and means for attaching the dielectric bar the fastening means comprising a plurality of dielectric fasteners connecting the dielectric bar to at least one of the side edges;

 the step of producing the dielectric bar comprises providing a dielectric bar and means for attaching the dielectric bar, the attachment means comprising a plurality of dielectric fasteners integral with said dielectric bar, the dielectric bar and the means fasteners being provided away from the core layer;

 - The assembly step of the layers comprises fixing the central layer to the lower layer, and then removing the attachment means, by cutting, once the central layer attached to the lower layer;

 the step of supplying one of the upper layer and the lower layer comprises the embodiment of the dielectric bar, said dielectric bar being arranged or intended to be disposed in said layer, so that after the step of assembly, the dielectric bar is disposed in the propagation zone and is delimited in said layer;

the median plane at the lateral edges of the cavity forms a plane of symmetry of the assembly formed by the dielectric fasteners; the dielectric fasteners extend only from one of the lateral edges;

each dielectric fastener has a straight bar shape and extends from one of the lateral edges;

 at least a part of the fastening means is not removed during the layer assembly step, said part of the fastening means then forming a functional fastening component, the non-withdrawn dielectric fasteners being configured to performing a filter function for an electromagnetic wave propagating in the propagation zone;

 the method comprises a step of feeding the microwave component with an electromagnetic wave propagating in the propagation zone, the electromagnetic wave having at least one propagation mode having two maximum electric fields, the or each dielectric bar being located in the cavity at one of said maximums;

 the dielectric bar is a first dielectric bar, the production stage being a step of producing the first dielectric bar and a second dielectric bar, the step of producing the first dielectric bar and the second dielectric bar being implemented during the cutting of said plurality of recesses; said plurality of cutout recesses defining the first dielectric bar, the second dielectric bar and means for attaching the first dielectric bar and the second dielectric bar; the fastening means comprising a plurality of first dielectric fasteners connecting the first dielectric bar to one of the side edges and a plurality of second dielectric fasteners connecting the second dielectric bar to the other of the side edges;

 - After assembly, the dielectric bar has a surface defining the cavity;

 the step of supplying one of the upper layer and the lower layer comprises the provision of an initial layer, the initial layer being intended to form said layer and comprising at least one dielectric underlayer, a sub-layer; an electrically conductive upper layer, and an electrically conductive lower sublayer; the embodiment of the dielectric bar comprising the implementation of lateral boundaries in said initial layer and the removal of at least a portion of one of the electrically conductive sub-layers of the initial layer extending between the two lateral boundaries;

- The dielectric bar is a first dielectric bar, a step of providing the upper layer or the lower layer comprising the production of a second dielectric bar; and, after assembly, the cavity is filled with a fluid having a dielectric constant, or defines a sealed closed volume and is empty of fluid.

 The invention will be better understood on reading the description which follows, given solely by way of example, and with reference to the appended drawings, in which:

 - Figure 1 is a schematic top section of a first microwave component according to the invention, said section passing through the dielectric bar;

 FIG. 2 is a diagrammatic cross-sectional view of the first component of FIG. 1;

 - Figure 3 is a schematic cross-sectional view of the first component in the first manufacturing process;

 - Figure 4 is a schematic top sectional view of the first component in a first embodiment of a manufacturing method according to the invention, said section passing through the dielectric bar;

 - Figure 5 is a schematic top sectional view of the first component in a variant of the manufacturing method of the first component according to the invention, said section passing through the dielectric bar;

 - Figure 6 is a schematic cross-sectional view of a second microwave component according to the invention;

 - Figure 7 is a schematic top section of a third microwave component according to the invention, said section passing through the dielectric bar;

 - Figure 8 is a schematic top section of a fourth component according to the invention, said section passing through the dielectric bar;

 - Figure 9 is a schematic top sectional view of a fifth microwave component according to the invention, said section passing through the dielectric bar;

 Fig. 10 is a schematic cross-sectional view of the fifth component of Fig. 9;

 FIGS. 11 to 17 are diagrammatic sectional views of a sixth, a seventh, an eighth, a ninth, a tenth, an eleventh and a twelfth component respectively. the invention.

 A first microwave component 10A according to the invention is illustrated in the figures

1 and 2. The first component 10A is for example a filter, in particular a microwave passband, lowpass, highpass or bandpass filter. In a variant, the first microwave component 10A is for example a transmission line, a multiplexer, a coupler, a divider, a combiner, an antenna, an oscillator, an amplifier, a load, a circulator, a resonator, a shifter phase or an insulator.

 The first component 10A is here of the type "integrated guide to the substrate".

 The first component 10A comprises a waveguide 12 adapted to guide an electromagnetic wave along an axis of propagation X-X, the electromagnetic wave having in particular a wavelength greater than or equal to a predetermined minimum wavelength.

 The waveguide 12 comprises an upper layer 14, a lower layer 16, and a central layer 18 interposed between the upper layer 14 and the lower layer 16, said layers 14, 16, 18 defining a propagation zone 19 of the electromagnetic wave, the propagation zone 19 extending along the axis of propagation XX.

 The waveguide 12 further comprises at least one dielectric bar 28 disposed in the propagation zone 19.

 Subsequently, the term "dielectric element" means that said element has a relative dielectric permittivity greater than or equal to 1.

 The dielectric material may have absorbent properties, i.e., loss tangent coefficient greater than 0.004, to provide an attenuator function.

 Each of the upper 14, lower 16 and central layers 18 extends parallel to a plane XY, defined by the axis of propagation X-X and a transverse axis Y-Y orthogonal to the axis of propagation X-X.

 Each of the upper 14, lower 16 and central 18 layers has an upper surface 20A, 20B, 20C and a lower surface 21A, 21B, 21C.

 In the first component 10A, each of said upper surfaces 20A, 20B, 20C and each of said lower surfaces 21A, 21B, 21C are electrically conductive.

Subsequently, the term "electrically conductive element" means that said element has an electrical conductivity greater than 1 ^* 10 ⁶ Sm ¹ , preferably equivalent to that of a metal of the copper, silver, aluminum or gold type.

The lower layer 16 and the upper layer 14 are arranged at a distance from one another, on either side of the central layer 18, in contact with the central layer 18. In particular, the lower surface 21A of the upper layer 14 is in contact with the upper surface 20C of the central layer 18. Similarly, the lower surface 21C of the central layer 18 is in contact with the upper surface 20B of the lower layer 16.

 Thus, the upper layer 14, the lower layer 16 and the central layer 18 form a stack.

 The lower surface 21A of the upper layer 14 is electrically connected to the upper surface 20C of the central layer 18. Similarly, the lower surface 21C of the central layer 18 is electrically connected to the upper surface 20B of the lower layer 16 .

 In the remainder of the description, the term "transverse direction" Y-Y will be called a direction parallel to the transverse axis Y-Y.

 A transverse direction is thus a direction orthogonal to the axis of propagation X-X and parallel to the lower surface 21 A of the upper layer 14.

 In a preferred embodiment, each of the upper 14, lower 16 and central 18 layers forms a substrate.

 Each of the upper 14, lower 16 and central 18 layers thus comprises an electrically conductive upper sub-layer 22A, 22B, 22C, an electrically conductive lower sub-layer 24A, 24B, 24C and a dielectric core sub-layer 26A, 26B, 26C , having a first dielectric constant, interposed between the upper sub-layer 22A, 22B, 22C and the lower sub-layer 24A, 24B, 24C.

 In addition, the lower sub-layer 24A of the upper layer 14 is electrically connected to the upper sub-layer 22C of the central layer 18. Similarly, the lower sub-layer 24C of the central layer 18 is electrically connected to the sub-layer. upper layer 22B of the lower layer 16.

 The upper sub-layers 22A, 22B, 22C and the lower sub-layers 24A, 24B, 24C are for example made of copper.

 The central sub-layers 26A, 26B, 26C are for example made of epoxy resin or Teflon.

 The propagation zone 19 corresponds to an area in which the electromagnetic wave is confined during its propagation in the waveguide 12.

In the first component 10A of Figures 1 and 2, the propagation zone 19 is delimited by the lower electrically conductive sub-layer 24A of the upper layer 14, the upper sub-layer 22B electrically conductive lower layer 16 and two lateral boundaries central units 30 each arranged in the central layer 18 and spaced apart from each other. In addition, the propagation zone 19 comprises a cavity 32 delimited by the upper layer 14, by the lower layer 16, and laterally by the central layer 18.

 The central lateral boundaries 30 of the propagation zone 19 are adapted to prevent the passage of an electromagnetic wave having a wavelength greater than or equal to the predetermined minimum wavelength.

 Each central lateral boundary 30 electrically connects the lower sub-layer 24A of the upper layer 14 and the upper sub-layer 22B of the upper layer 14 therebetween.

 The central lateral boundaries 30 extend parallel to the axis of propagation X-X and are here parallel to each other.

 They extend in particular along the direction Z-Z orthogonal to the axis of propagation X-X and the transverse axis Y-Y.

 Subsequently, the terms "above" and "below" will be understood vis-à-vis the Z-Z direction.

 The central lateral boundaries 30 extend over the entire thickness of the central layer 18.

 They are in particular arranged laterally on either side of the cavity 32, for example here outside the cavity 32.

 In the embodiment of Figures 1 and 2, each central lateral border 30 comprises a row of electrically conductive vias 34, arranged at least through the central layer 18. By "via" is meant a hole, arranged at least through the central layer 18, having walls covered with an electrically conductive coating, for example metallized.

 More specifically, each via 34 extends in the direction Z-Z orthogonal to the axis of propagation X-X and to the transverse axis Y-Y, passing through at least the central layer 18.

 Each via 34 electrically connects the lower sub-layer 24A of the upper layer 14 and the upper sub-layer 22B of the upper layer 14 between them.

The spacing between two successive vias 34 of a central lateral border 30 is less than the predetermined minimum wavelength, in particular less than one-tenth of the predetermined minimum wavelength, preferably less than one twentieth of the length of the wavelength. predetermined minimum wave. In the example illustrated in FIGS. 1 and 2, the cavity 32 is delimited by the lower surface 21 A of the upper layer 14, the upper surface 20B of the lower layer 16 and the lateral edges 36 of the central layer 18.

 The cavity 32 is filled with a fluid 38 having a second dielectric constant, for example less than the first dielectric constant.

 The fluid 38 is for example air. Alternatively, in the case where the cavity 32 defines a sealed closed volume, it is filled with air, nitrogen or is empty of fluid.

 As illustrated in FIG. 1, the lateral edges 36 of the central layer 18 extend parallel to the X-X propagation axis.

 The lateral edges 36 of the central layer 18 extend in particular orthogonally and to the transverse axis Y-Y.

 The lateral edges 36 of the central layer 18 follow the central lateral boundaries 30. By "longer" is meant that the lateral edges 36 are in contact with said central lateral borders 30 or disposed at a distance, for example constant, from said lateral boundaries. central 30, this distance being preferably less than 100 pm.

 In the first component 10A illustrated in FIGS. 1 and 2, the dielectric bar 28 is disposed in the cavity 32, away from the lateral edges 36 of the cavity 32.

 In particular, the dielectric bar 28 is disposed in the propagation zone 19 such that, in projection on the upper surface 20B of the lower layer 16, said dielectric bar 28 is away from the lateral edges 36 of the cavity 32.

 The dielectric bar 28 is disposed between the lateral edges 36 of the cavity 32.

The dielectric bar 28 has an elongate shape here and extends in a longitudinal direction parallel to the axis of propagation. In addition, the dielectric bar 28 extends here orthogonally to the transverse axis Y-Y.

 In the example illustrated in FIG. 1, the dielectric bar 28 has a width comprised in particular between 1% and 90% of the width of the cavity 32.

 By "width of an element" is meant the edge-to-edge distance of the element taken along the transverse axis Y-Y.

 The width of the dielectric bar 28 is for example constant along the axis of propagation X-X, as illustrated in FIG.

 The dielectric bar 28 is here centered on a median plane of the two lateral edges 36.

In this example, the dielectric bar 28 has a thickness less than the height of the cavity 32. By "thickness of an element" or "height of an element", we hear the edge-to-edge distance of the element, taken in the direction ZZ orthogonal to the axis of propagation XX and the transverse axis YY.

 It is here disposed away from the lower surface 21A of the upper layer 14 and the upper surface 20B of the lower layer 16.

 The dielectric bar 28 is fixed to the upper surface 20B of the lower layer 16 via a lower contact sub-layer 40. More precisely, it is attached to the lower contact sub-layer 40, the sub-layer 40 lower contact layer 40 being attached to the upper surface 20B of the lower layer 16. The lower contact sub-layer 40 is electrically conductive.

 The dielectric bar 28 is further fixed to the lower surface 21A of the upper layer 14 via an upper contact sub-layer 42. More specifically, it is attached to the upper contact sub-layer 42, the upper contact sub-layer 42 being attached to the lower surface 21A of the upper layer 14. The upper contact sub-layer 42 is electrically conductive.

 A first manufacturing method relating to the manufacture of the first component 10A according to the invention will now be described, with reference to FIGS. 3 and 4.

 The first method comprises providing the upper layer 14 and the lower layer 16.

 It also includes the provision of the core layer 18, the core layer 18 being provided by having a plurality of recesses 44 therein, said plurality of recesses 44 being intended to form the cavity 32 of the first component 10A.

 The upper layer 14, the lower layer 16 and the core layer 18 are provided apart from each other.

 In the first method, the step of providing the central layer 18 comprises the provision of an initial layer 46, the initial layer 46 being intended to form the central layer 18.

 The initial layer 46 thus comprises at least one initial dielectric sublayer 48, having the first dielectric constant, which is intended in particular to form the central sub-layer 26C of the central layer 18.

 In particular, the initial layer 46 also comprises an initial electrically conductive upper underlayer 50 intended to form the upper sub-layer 22C of the central layer 18, and an electrically-conductive lower lower sublayer 52 intended to form the underlayer lower 24C of the central layer 18.

 The initial layer 46 is provided with no recess.

The step of supplying the central layer 18 then comprises cutting, in the initial layer 46 of the plurality of recesses 44 intended to form the cavity 32. The cut is implemented throughout the thickness of the initial layer 46.

Before or after said cutting step, the first method comprises a step of implementing the central lateral boundaries 30.

 For example, the implementation of the central lateral borders 30 comprises the realization of said rows of vias 34.

 In the first method, the step of supplying the central layer 18 further comprises producing the dielectric bar 28.

 The embodiment of the dielectric bar 28 is here implemented during the cutting of said plurality of recesses 44. Said plurality of recesses 44 is then intended to delimit the cavity 32, the dielectric bar 28 and attachment means 54 of the dielectric bar 28.

 During cutting, the dielectric bar 28 is more precisely formed by a portion of the initial dielectric underlayer 48 of the initial layer 46.

 The dielectric bar 28 is thus disposed in the initial layer 46. At the right of the dielectric bar 28, the initial and lower electrically conductive sub-layers 50, 52 of the initial layer 46 respectively above and below the dielectric bar 28 respectively form the upper contact sub-layer 42 and the lower contact sub-layer 40 of the first component 10A.

 As illustrated in FIG. 4, the fastening means 54 comprise a plurality of dielectric fasteners 56 connecting the dielectric bar 28 to at least one of the lateral edges 36 of the cavity 32.

 Thus, the dielectric bar 28, the dielectric fasteners 56 and the side edges 36 of the cavity 32 are integral.

 As illustrated in FIG. 4, each dielectric fastener 56 has a straight bar shape, and here extends perpendicularly from one of the lateral edges 36.

 In the example illustrated in FIG. 4, at least one dielectric fastener 56 extends from each of the lateral edges 36.

 The dielectric fasteners 56 are spaced apart from each other.

 In the first method, as illustrated in FIG. 4, the spacing separating two adjacent dielectric fasteners 56 is equal for all the dielectric fasteners 56.

 In projection on the propagation axis X-X, each dielectric fastener 56 extends from one of the lateral edges 36 is disposed substantially in the middle of two adjacent dielectric fasteners 56 extending from the opposite lateral edge 36.

The embodiment of the dielectric bar 28 comprises, for example, the suppression of the initial upper and lower sublayers 50, 52 that are electrically conductive to the straight of the dielectric fasteners 56, especially above and below the dielectric fasteners 56.

 In this example, the dielectric fasteners 56 have a thickness less than the height of the cavity 32.

 At the end of the step of producing the dielectric bar 28 and the cutting step, the initial layer 46 forms the central layer 18.

 At the end of the embodiment step, the dielectric bar 28 is disposed between a plane defined by the upper surface 20C of the central layer 18 and a plane defined by a lower surface 21C of the central layer 18.

 The dielectric bar 28 is thus intended to be disposed in the cavity 32, between the lateral edges 36.

 Subsequently, the first method comprises assembling the upper layer 14, the lower layer 16 and the central layer 18, so that the central layer 18 is interposed between the upper layer 14 and the lower layer 16.

 During the entire manufacturing process, the layers 14, 16, 18 are aligned relative to each other by means of centering pins or by camera with patterns.

 As illustrated in FIG. 3, the assembly firstly comprises the attachment of the central layer 18 to the lower layer 16. This attachment is for example made by gluing.

 During this fixing step, the dielectric bar 28 is likewise fixed to the lower layer 16.

 During the entire duration of this fixation, the dielectric bar 28 is held in position relative to the central layer 18 and to the lower layer 16 by the dielectric fasteners 56. The positioning of the dielectric bar 28 is therefore very precise and chosen when the cutting step.

 In the first method, the assembly then comprises the removal of the fastening means 54, once the central layer 18 has been fastened to the lower layer 16, in particular once the dielectric bar 28 has been fastened to the lower layer 16.

 This removal is implemented by cutting the fastening means 54, and in particular by cutting the dielectric fasteners 56. The preceding step of removing the upper and lower sub-layers initial electrically conductive 50, 52 facilitates this step of cutting dielectric fasteners 56.

This cutting is for example performed manually with a scalpel, with a digital milling machine, or with a laser. Each dielectric fastener 56 is preferably cut flush with the side edge 36 from which it extends.

 In addition, each dielectric fastener 56 is advantageously cut off flush with the dielectric bar 28.

 Subsequently, the assembly comprises the attachment of the upper layer 14 to the central layer 18. This attachment is for example made by gluing.

 During this fixation, the cavity 32 is then formed by said plurality of recesses 44 being delimited by the upper layer 14, by the lower layer 16, and laterally by said opposite lateral edges 36 of the central layer 18.

 After assembly, the first component 10A is formed. In particular, the layers 14, 16, 18 define the propagation zone 19 of an electromagnetic wave.

 The propagation zone 19 is then delimited by the electrically conductive lower sublayer 24A of the upper layer 14, the upper electrically conductive sub-layer 22B of the lower layer 16 and the central lateral boundaries 30.

 This propagation zone 19 comprises the cavity 32.

 After the assembly step, the dielectric bar 28 is disposed in the cavity 32 away from the lateral edges 36 of the cavity 32.

 In particular, after the assembly step, the dielectric bar 28, disposed in the central layer 18, is disposed in the propagation zone 19, and, in projection on the upper surface 20B of the lower layer 16, to the distance from the lateral edges 36 of the cavity 32.

 In use, the first method comprises a step of feeding the first microwave component 10A with an electromagnetic wave propagating in the propagation zone 19. The electromagnetic wave has at least one propagation mode having a maximum of electric field.

 The dielectric bar 28 is positioned in the cavity 32 at a predetermined position such that, during this step of supplying the first component 10A, the predetermined position corresponds to the level of said maximum electric field.

 More specifically, during the step of producing the dielectric bar 28, the dimensions of the dielectric fasteners 56 are predetermined so that, after assembly, the dielectric bar 28 is located in the cavity 32 at the predetermined position.

The dielectric bar 28 thus has an effect on said mode of propagation. In particular, the dielectric bar 28 charges the waveguide 12 so as to widen the monomode bandwidth. In addition, in use, the structure comprising three layers 14, 16, 18 makes the first component 10A compact and flexible.

 As a variant not shown of the first component 10A, the waveguide 12 comprises a first electrically insulating layer between the lower sublayer 24A of the upper layer 14 and the upper sub-layer 22C of the central layer 18, and / or one second electrically insulating layer between the lower sublayer 24C of the central layer 18 and the upper sub-layer 22B of the lower layer 16.

 The insulating layer or layers are for example made in prepreg.

 Each central lateral border 30, and in particular each via 34, passes through the insulating layer or layers.

 As a variant not shown of the first component 10A, the dielectric bar 28 is not centered on a median plane of the two lateral edges 36 but is shifted laterally of said median plane. Such a lateral shift makes it possible to provide a control of the desired modes of propagation of the electromagnetic wave propagating in the waveguide 12.

 As a variant not shown of the first component 10A, the width of the dielectric bar 28 varies along the axis of propagation.

 In a variant not shown of the first component 10A, the waveguide 12 comprises electrically conductive wires passing through the cavity 32 from one side to the other, and electrically connecting the lower sub-layer 24A of the upper layer 14 to the upper layer 22B of the lower layer 16. These wires make it possible to perform impedance matching to another circuit.

 In a variant not shown of the first component 10A, the waveguide 12 comprises electrically conductive wires passing through the cavity 32, being electrically connected to the lower sub-layer 24A of the upper layer 14, and having a free end away from of the upper layer 22B of the lower layer 16. These son allow to make capacitive pads for adjusting the filtering properties of the component.

 A variant of the first method of manufacturing the first component 10A is illustrated in FIG.

 This variant differs from the first method described in that the median plane of the two lateral edges 36 is a plane of symmetry of the dielectric fasteners 56.

In addition, each dielectric fastener 56 does not extend perpendicularly from one of the lateral edges 36. At least two dielectric fasteners 56 extend from the same side edge 36, joining at the dielectric bar 28. As shown in FIG. 5, these two dielectric fasteners 56 form a repeating pattern along the axis of propagation.

 More generally, for each dielectric fastener 56, another dielectric fastener 56 extends from the same side edge 36, joining at the level of the dielectric bar 28.

 As a variant not shown of the first manufacturing method, the embodiment of the dielectric bar 28 does not include the removal of the initial and lower electrically conductive upper and lower sub-layers 50, 52 to the right of the dielectric fasteners 56. These sub-layers 50, 52 are removed. when removing the attachment means 54.

 In a variant not shown of the first manufacturing method, the dielectric fasteners 56 extend from only one of the lateral edges 36.

 A second microwave component 10B will now be described, with reference to FIG.

 This second component 10B differs from the first component 10A in that the dielectric bar 28 and the lower surface 21A of the upper layer 14 delimit a free space between them.

 The dielectric bar 28 is thus not fastened to the lower surface 21A of the upper layer 14 via the upper contact sub-layer 42.

 The waveguide 12 is then devoid of said upper contact sub-layer 42.

 A second manufacturing method relating to the manufacture of the second component 10B differs from the first method in that the embodiment of the dielectric bar 28 comprises the removal of the initial upper electrically conductive underlayer 50 above the dielectric bar 28.

 A third microwave component 10C will now be described, with reference to FIG. 7.

 This third component 10C differs from the first component 10A in that the waveguide 12 further comprises a functional fastening component 58.

 The functional fastening component 58 is formed by a plurality of dielectric fasteners 56 integral with the dielectric bar 28, each dielectric fastener 56 extending from one of the side edges 36.

Said dielectric fasteners 56 have characteristics identical to the dielectric fasteners described in the first method. In the third component 10C shown in FIG. 7, the dielectric fasteners 56 extend from only one of the side edges 36.

 The dielectric bar 28 is thus spaced from the lateral edges 36 in at least one region of the dielectric bar 28.

 In addition, the dielectric clips 56 are configured to perform a filter function for an electromagnetic wave propagating in the propagation zone 19.

 In particular, the distribution, the spacing between two adjacent dielectric fasteners 56, and their dimensions are predetermined to perform said function.

 A third manufacturing method relating to the manufacture of the third component 10C differs from the first method in that at least a part of the attachment means 54 is not removed during the assembly step.

 The upper layer 14 is fixed to the central layer 18 without removing all the dielectric fasteners 56.

 Said part of the fastening means 54 then form the functional fastening component 58, the non-withdrawn dielectric fasteners 56 being configured to perform the filter function for an electromagnetic wave propagating in the propagation zone 19.

 In particular, during the step of producing the dielectric bar 28, the distribution, the spacing between two adjacent dielectric fasteners 56, and their dimensions are predetermined to perform said function.

 As a variant not shown of the third component 10C, the width of the dielectric bar 28 varies along the axis of propagation.

 In a variant not shown of the third component 10C, the width of the dielectric bar 28 is constant between two dielectric fasteners 56 adjacent, and the width of the dielectric bar 28 between a pair of adjacent dielectric fasteners 56 is different for at least two pairs of dielectric adjacent dielectric fasteners 56.

 In another variant not shown of the third component 10C, the width of the dielectric bar 28 taken at a dielectric fastener 56 is different from the width of the dielectric bar 28 taken at an adjacent dielectric attachment 56. The side of the bar dielectric 28 joining said two adjacent dielectric fasteners 56 then having in plan view a predetermined profile selected from: a straight line or a curve.

A fourth component 10D according to the invention is illustrated in FIG. This fourth component 10D differs from the first component 10A in that the dielectric bar 28 is made of a dielectric material different from the material in which the central sub-layer 26C of the central layer 18 is made.

 The dielectric bar 28 is in contact with the upper surface 20B of the lower layer 16.

 In particular, the dielectric bar 28 is fixed to the upper surface 20B of the lower layer 16, for example by gluing.

 In this example, the dielectric bar 28 is in contact with the lower surface 21A of the upper layer 14. In other words, it has a thickness equal to the height of the cavity 32.

 In particular, the dielectric bar 28 is fixed to the lower surface 21A of the upper layer 14, for example by gluing.

 As a variant, not shown, of the fourth component 10D, the dielectric bar 28 and the lower surface 21A of the upper layer 14 delimit a free space between them. In other words, the dielectric bar 28 is devoid of contact with the lower surface 21A of the upper layer 14. The thickness of the dielectric bar 28 is therefore less than the thickness of the central layer 18.

 In a non-illustrated variant of the fourth component 10D, the waveguide 12 comprises a functional fastening component 58 similar to the functional fastening component 58 of the third component 10C.

 A fourth manufacturing method relating to the manufacture of the fourth component 10D will now be described.

 The fourth method differs from the first method in that the dielectric bar 28 and the attachment means 54 are not cut in the central layer 18, and in that the step of producing the dielectric bar 28 comprises the supply of the dielectric bar 28 and attachment means 54 of the dielectric bar 28, the dielectric bar 28 and the attachment means 54 being provided away from the central layer 18.

 Central layer 18 is provided having a recess 44 for forming cavity 32 alone.

 The attachment means 54 have characteristics identical to the fastening means of the first method but differ from the latter in that the dielectric fasteners 56 are not integral with the lateral edges 36 of the cavity 32.

The fastening means 54 thus comprise the plurality of dielectric fasteners 56 integral with the dielectric bar 28, the dielectric fasteners 56 being integral with the dielectric bar 28, for example integral with the dielectric bar 28. The dielectric bar 28 and the dielectric fasteners 56 are preferably made of a dielectric material different from the material in which the central sub-layer 26C of the central layer 18 is made. In a variant, they are made of the same material as that of the central underlayer 26C of the central layer 18.

 During assembly, the dielectric bar 28 is fixed to the lower layer 16.

The dielectric bar 28 is held in position relative to the lower layer 16, by the dielectric fasteners 56 for the duration necessary for its attachment to the lower layer 16.

 Subsequently, the central layer 18 is fixed to the lower layer 16, the dielectric bar 28 then being arranged in the recess 44.

 A fifth component 10E according to the invention is illustrated in FIGS. 9 and 10.

This fifth component 10E differs from the first component 10A in that the cavity 32 is delimited along the axis of propagation between a front end 60 and a rear end 62 of the central layer 18, the dielectric bar 28 extending from the end before 60 at the rear end 62.

 The cavity 32 has, in projection on the upper surface 20B of the lower layer 16, a closed outer contour.

 As illustrated in FIG. 9, the fifth component 10E further comprises two auxiliary transmission lines 64, arranged longitudinally on either side of the cavity 32, the propagation zone 19, and the central lateral boundaries 30, extending into each of these two additional transmission lines 64.

 Each transmission transmission line 64 comprises an upper electrically conductive upper layer 66, identical to the upper layer 14 and integrally formed with the upper layer 14, an electrically conductive lower layer, identical to the lower layer 16 and integrally formed with the lower layer 16, and a central dielectric layer 68, identical to the central layer 18 and integral with the central layer 18.

 The auxiliary transmission lines 64 are devoid of cavity 32.

 The spacing, taken along the transverse axis Y-Y, between the central lateral boundaries 30 is greater in the cavity 32 at their spacing in the adjoining transmission lines 64.

 The dielectric bar 28 is integral with the central sub-layer 26C of the central layer 18. In particular, the dielectric bar 28 is here integral with the central sub-layer 26C of the central layer 18.

The dielectric bar 28 is thus integral with the central appendix layer 68 of each of the associated transmission lines 64. The dielectric bar 28 has a length equal to the length of the cavity 32. "Length of an element" means the edge-to-edge distance of the element taken along the axis of propagation.

 In addition, the embodiment of the fifth component 10E illustrated in FIG. 10 differs from the first component 10A in that, in at least one portion of the cavity 32, taken along the transverse axis YY, the dielectric bar 28 defines respectively with the lower surface 21A of the upper layer 14 and the upper surface 20B of the lower layer 16 a free space.

 More specifically, the upper appendix layers 66 and the lower auxiliary layers protrude into the cavity 32 respectively above and below the dielectric bar 28. In projection on the upper surface 20B of the lower layer 16, said projections in the cavity 32 of the upper appendages 66 and lower layers attached have a pointed shape.

 A fifth manufacturing method relating to the manufacture of the fifth component 10E will now be described.

 The fifth method differs from the first method in that during the cutting of said plurality of recesses 44, said plurality of recesses 44 is intended to delimit the cavity 32, along the axis of propagation, between a front end 60 and a rear end 62 of the central layer 18.

 During cutting, said plurality of recesses 44 is intended to define the cavity 32 as it has, in projection on the upper surface 20B of the lower layer 16, a closed outer contour.

 Said plurality of recesses 44 cut out delimits the dielectric bar 28, the dielectric bar 28 extending from the front end 60 to the rear end 62, and having in particular a length equal to the length of the cavity 32.

 For example, said plurality of recesses 44 delimits the dielectric bar 28 without delimiting dielectric fasteners 56 connecting the dielectric bar 28 to the remainder of the central layer 18.

 In addition, the implementation of the central lateral boundaries 30 is implemented such that, after assembly, the propagation zone 19 extends longitudinally on either side of the cavity 32. The upper layer 14, the lower layer 16 and the the central layer 18 then define, on either side of the cavity 32, the two additional transmission lines 64.

In use, during the step of feeding the fifth 10E microwave component with an electromagnetic wave, the wave propagates in the propagation zone 19 in one of the transmission lines 64. The projections of the upper and lower auxiliary layers 66 make it possible to ensure a good electromagnetic transition for the wave propagating in the propagation zone 19 between the adjoining transmission lines 64 and the cavity 32.

 A sixth component 10F microwave will now be described, with reference to Figure 1 1.

 This sixth component 10F differs from the previous embodiments in that the central lateral boundaries 30 do not include rows of vias 34.

 Each central lateral border 30 comprises an electrically conductive continuous side wall 70.

 Said continuous side wall 70 is in particular formed by an electrically conductive coating, for example a metallic coating. Said coating is here applied to the lateral edges 36 of the cavity 32.

 "Continuous side wall" means that the metal coating is applied over the entire height and length of the side edges 36.

 The central lateral borders 30 are in particular devoid of vias.

 A sixth manufacturing method relating to the manufacture of the sixth component 10F will now be described.

 The sixth method differs from the first method in that the step of implementing the central lateral boundaries 30 is implemented after the step of cutting said plurality of recesses 44.

 This step of implementation of the central lateral boundaries 30 comprises the realization of an electrically conductive continuous side wall 70, by the application of an electrically conductive coating, for example metal, on edges of said plurality of recesses 44, these edges being intended to form the lateral edges 36 of the cavity 32.

 A seventh component 10G according to the invention will now be described with reference to FIGS.

 This seventh component 10G differs from the first component 10A in that the dielectric bar 28 is a first dielectric bar 28, and in that the waveguide 12 further comprises a second dielectric bar 72.

 The second dielectric bar 72 is disposed in the cavity 32, away from said first dielectric bar 28, and away from the side edges 36 of the cavity 32.

In particular, the second dielectric bar 72 is disposed in the propagation zone 19 such that, in projection on the upper surface 20B of the lower layer 16, said second dielectric bar 72 is away from the lateral edges 36 of the cavity 32 . The second dielectric bar 72 is disposed between the lateral edges 36 of the cavity 32.

 The first dielectric bar 28 and the second dielectric bar 72 extend respectively in a longitudinal direction parallel to the axis of propagation X-X. In addition, they extend here orthogonally to the transverse axis Y-Y.

 The first dielectric bar 28 and the second dielectric bar 72 are offset laterally from the median plane of the two lateral edges 36.

 In the example illustrated in FIG. 12, the second dielectric bar 72 is at least partially disposed between the first dielectric bar 28 and one of the lateral edges 36.

 The second dielectric bar 72 is substantially similar to the first dielectric bar 28.

 The second dielectric bar 72 has a width comprised in particular between 1% and 90% of the width of the cavity 32.

 The width of the second dielectric bar 72 is for example constant along the axis of propagation X-X. Alternatively, the width of the second dielectric bar 72 varies along the axis of propagation.

 The second dielectric bar 72 has in this example a thickness less than the height of the cavity 32.

 It is here disposed away from the lower surface 21A of the upper layer 14 and the upper surface 20B of the lower layer 16.

 The second dielectric bar 72 is fixed to the upper surface 20B of the lower layer 16 via a second lower contact sub-layer 74. More specifically, it is attached to the second lower contact sub-layer 74, the second lower contact sub-layer 74 being attached to the upper surface 20B of the lower layer 16. The second lower contact sub-layer 74 is electrically conductive.

 The second dielectric bar 72 is further attached to the lower surface 21A of the upper layer 14 via a second upper contact sub-layer 76. More specifically, it is attached to the second upper sub-layer of contact 76, the second upper contact sub-layer 76 being attached to the lower surface 21A of the upper layer 14. The second upper contact sub-layer 76 is electrically conductive.

A seventh manufacturing method relating to the manufacture of the seventh component 10G will now be described. The seventh method differs from the first method in that the step of providing the central layer 18 comprises a step of producing the first dielectric bar 28 and the second dielectric bar 72.

 The realization of the first dielectric bar 28 and the second dielectric bar 72 being implemented here during the cutting of said plurality of recesses 44.

 During the cutting of said plurality of recesses 44, said plurality of recesses 44 is intended to delimit the first dielectric bar 28, the second dielectric bar 72 and attachment means 54 of the first dielectric bar 28 and the second dielectric bar 72.

 During cutting, the first dielectric bar 28 and the second dielectric bar 72 are more precisely formed by a portion of the initial dielectric underlayer 48 of the initial layer 46.

 At the right of the second dielectric bar 72, the initial and lower electrically conductive upper and lower sub-layers 50, 52 of the initial layer 46, respectively above and below the second dielectric bar 72, form respectively the second upper sub-layer of contact 76 and the second lower contact sub-layer 74 of the first component 10A.

 The fastening means 54 comprise a plurality of first dielectric fasteners connecting the first dielectric bar 28 to one of the side edges 36 of the cavity 32. They further comprise a plurality of second dielectric fasteners connecting the second dielectric bar 72 to the other side edges 36 of the cavity 32.

 For example, the fastening means 54 comprise a plurality of intermediate dielectric fasteners connecting the first dielectric bar 28 to the second dielectric bar 72.

 The first dielectric fasteners, the second dielectric fasteners and the intermediate dielectric fasteners have substantially identical characteristics to the dielectric fasteners 56 described in the first method.

 As in the first method, in use, the seventh method comprises a step of supplying the seventh 10G microwave component with an electromagnetic wave propagating in the propagation zone 19.

 The electromagnetic wave here has at least a first and a second propagation mode, the second propagation mode having two maximums of electric field.

The first dielectric bar 28 and the second dielectric bar 72 are respectively positioned in the cavity 32 at a first predetermined position and at a second predetermined position such that, during this step of supplying the seventh component 10G, the first predetermined position and the second predetermined position respectively correspond to the levels of said electric field maximums.

 More precisely, during the step of producing the dielectric bar 28, the dimensions of the first fasteners and the second fasteners are predetermined so that, after assembly, the first dielectric bar 28 and the second dielectric bar 72 are respectively located in the cavity 32 at the level of said maximum electric fields.

 The first dielectric bar 28 and the second dielectric bar 72 thus have an effect on the second mode of propagation. In particular, they reduce the monomode band of the seventh component 10G to obtain a controlled dual mode structure.

 An eighth component 10H will now be described, with reference to FIG. 13.

This eighth component 10H differs from the fourth component 10D in that the dielectric bar 28 is a first dielectric bar 28, and in that the waveguide 12 comprises at least one other dielectric bar 72.

 In the example illustrated in FIG. 13, the waveguide 12 comprises at least three other dielectric bars 72.

 Each other dielectric bar 72 is disposed in the cavity 32, away from said first dielectric bar 28, away from each other dielectric bar 72 and away from the side edges 36 of the cavity 32.

 In particular, each other dielectric bar 72 is disposed in the propagation zone 19 such that, in projection on the upper surface 20B of the lower layer 16, said other dielectric bar 72 is away from the lateral edges 36 of the cavity 32 .

 Each other dielectric bar 72 is disposed between the lateral edges 36 of the cavity 32.

 The first dielectric bar 28 and each other dielectric bar 72 extend respectively in a longitudinal direction parallel to the axis of propagation X-X. In addition, they extend here orthogonally to the transverse axis Y-Y.

 The first dielectric bar 28 and each other dielectric bar 72 are offset laterally from the median plane of the two lateral edges 36.

In projection on the upper surface 20B of the lower layer 16, the first dielectric bar 28 and each other dielectric bar 72 define respectively a circular outer contour. The term "bar" is here to be taken in a broad sense.

 In the example illustrated in FIG. 13, each other dielectric bar 72 is substantially similar to the first dielectric bar 28. In particular, they have a substantially identical diameter here.

 The first dielectric bar 28 and each other dielectric bar 72 then respectively have a dielectric permittivity greater than 6.

 An eighth manufacturing method relating to the manufacture of the eighth component 10H will now be described.

 The eighth method differs from the fourth method in that it comprises a step of producing each other dielectric bar 72. The step of producing each other dielectric bar 72 comprises the provision of said other dielectric bar 72 and attachment means of said another dielectric bar 72, said other dielectric bar 72 and the attachment means being provided away from the central layer 18.

 During assembly, each other dielectric bar 72 is fixed to the lower layer 16, in particular before the central layer 18 is fixed to the lower layer 16.

 As a variant of the eighth component 10H, in projection on the upper surface 20B of the lower layer 16, at least one of the first dielectric bar 28 and of each other dielectric bar 72 defines an outer contour having a rectangle, square, or oval shape.

 In yet another variant of the eighth component 10H, projected on the upper surface 20B of the lower layer 16, at least one of the first dielectric bar 28 and each other dielectric bar 72 defines a ring shape, having an outer contour of circular shape rectangular, square, or oval, and an inner contour of circular, rectangular, square, or oval shape.

 In yet another variant of the eighth component 10H, at least two bars of the first dielectric bar 28 and the other dielectric bars 72 are made of different materials.

 The eighth manufacturing method described allows to simultaneously mount several bars 28, 72 made of different materials.

As an alternative to the eighth component 10H, the waveguide 12 further comprises a functional fastening component formed by a plurality of dielectric fasteners integral with at least one of the bars 28, 72, each dielectric fastener extending to from one of the lateral edges 36. In the manufacturing process associated with this alternatively, at least a portion of the attachment means is not removed during the assembly step.

 A ninth component 101 according to the invention will now be described with reference to FIG.

 This ninth component 101 differs from the first component 10A in that the dielectric bar 28 is not disposed in the cavity 32.

 The dielectric bar 28 is disposed in the propagation zone 19 and is delimited in the upper layer 14. The dielectric bar 28 is thus formed in the upper layer 14.

 The dielectric bar 28 is formed in the central sub-layer 26A of the upper layer 14 and is defined by a portion of the upper sub-layer 22A electrically conductive of the upper layer 14 and laterally between two upper lateral boundaries 78.

 The dielectric bar 28 opens on the cavity 32.

 As illustrated in FIG. 14, the dielectric bar 28 has a surface 80 delimiting the cavity 32.

 The dielectric bar 28 is disposed between a plane defined by an upper surface 20C of the central layer 18 and a plane defined by an upper surface 20A of the upper layer 14.

 The upper layer 14 is devoid of lower sublayer 24A, in at least a portion of the upper layer 14 between the two upper lateral boundaries 78. In particular, in the example illustrated in FIG. 14, the upper layer 14 is entirely without lower underlayer 24A, between the two upper lateral boundaries 78.

 The dielectric bar 28 is here arranged in the propagation zone 19, such that, in projection on the upper surface 20B of the lower layer 16, the dielectric bar 28 is away from the lateral edges 36 of the cavity 32.

As in the first component 10A, the propagation zone 19 is delimited by the upper electrically conductive sub-layer 22B of the lower layer 16 and the two central lateral boundaries 30 each arranged in the central layer and spaced apart from each other . Furthermore, in the ninth component 101, the propagation zone 19 is delimited by the portion of the upper sub-layer 22A of the upper layer 14 extending above the dielectric bar 28, by a portion of the underlayer electrically conductive bottom 24A of the upper layer 14, and the upper lateral boundaries 78, the upper lateral boundaries 78 joining said parts. The upper lateral boundaries 78 are adapted to prevent the passage of an electromagnetic wave having a wavelength greater than or equal to the predetermined minimum wavelength.

 The upper lateral boundaries 78 are each arranged in the upper layer 14.

 The upper lateral boundaries 78 extend parallel to the axis of propagation X-X and are here parallel to each other.

 They extend in particular over the entire thickness of the upper layer 14.

The upper lateral boundaries 78 are spaced apart from each other.

 They are here in particular symmetrical to one another with respect to the median plane of the lateral edges 36. The dielectric bar 28 is thus centered here on the median plane of the lateral edges 36.

 A cross section of the propagation zone 19 has substantially a T-shape returned.

 In the example illustrated in FIG. 14, in projection on the upper surface 20B of the lower layer 16, the upper lateral boundaries 78 are disposed apart and between the lateral edges 36.

 Each upper lateral boundary 78 electrically connects the lower sub-layer 24A of the upper layer 14 and the upper sub-layer 22A of the upper layer 14 between them.

 The upper lateral boundaries 78 and the central lateral boundaries 30 electrically connect the upper sub-layer 22B of the lower layer 16 to the upper sub-layer 22A of the upper layer 14, respectively on either side of the cavity 32.

 In the embodiment of FIG. 14, each upper lateral frontier 78 comprises a row of electrically conductive vias 34 arranged through the upper layer 14. More precisely, each via 34 extends in the ZZ direction, crossing the layer superior 14.

 Each via 34 electrically connects the lower sub-layer 24A of the upper layer 14 and the upper sub-layer 22A of the upper layer 14 between them.

The distance between two successive vias 34 of an upper lateral border 78 is less than the predetermined minimum wavelength, in particular less than one-tenth of the predetermined minimum wavelength, preferably less than one twentieth of the length of the wavelength. predetermined minimum wave. A ninth method relating to the manufacture of the ninth component 101 will now be described.

 The ninth method differs from the first method in that the dielectric bar 28 is not cut in the central layer 18 and is not arranged in the cavity 32.

 In addition, no fastening means as described in the first method is cut in the central layer 18. In this embodiment, no fastener is used compared to the embodiments for arranging the dielectric bar 28 in the cavity 32.

 Central layer 18 is provided having a recess 44 for forming cavity 32 alone.

 The supply of the upper layer 14 comprises the provision of an upper initial layer, the upper initial layer being intended to form the upper layer 14.

 The upper initial layer thus comprises at least one initial dielectric sublayer, intended to form the central sub-layer 26A of the upper layer 14, an electrically conductive upper sub-layer, intended to form the upper sublayer 22A of the layer upper 14, and an electrically conductive lower sub-layer, for forming the lower sub-layer 24A of the upper layer 14.

 In the ninth method, the step of providing the upper layer 14 comprises the realization of the dielectric bar 28. The embodiment of the dielectric bar 28 comprises the implementation of the upper lateral boundaries 78 and the removal of at least a portion, preferably of the entirety of the electrically conductive lower sub-layer of the upper initial layer extending between the two upper lateral boundaries 78.

 The portion of the central dielectric sub-layer of the upper initial layer delimited between the upper lateral boundaries 78 forms said dielectric bar 28.

 At the end of the step of producing the dielectric bar 28, the upper initial layer forms the upper layer 14.

 During assembly, the central layer 18 is attached to the lower layer 16 and the upper layer 14 is fixed to the central layer 18 to form the ninth component 101.

Thus, after assembly, the propagation zone 19 comprises the dielectric bar 28 delimited in the upper layer 14, the dielectric bar 28 having a surface delimiting the cavity 32. As a variant, not shown, of the ninth component 101, the dielectric bar 28 is delimited in the lower layer 16. In the associated manufacturing method, the step of providing the lower layer 16 comprises the production of the dielectric bar 28.

 As a variant not shown of the ninth component 101, the dielectric bar 28 is not centered on the median plane of the lateral edges 36. In particular, the dielectric bar 28 is laterally offset from the median plane of the lateral edges 36.

 The upper lateral boundaries 78 are then devoid of symmetry with respect to the median plane of the lateral edges 36.

 A tenth component 10 J according to the invention will now be described with reference to FIG.

 This tenth component 10J differs from the ninth component 101 in that said dielectric bar 28 is a first dielectric bar 28.

 The waveguide 12 further comprises a second dielectric bar 72 disposed in the propagation zone 19 and delimited in the lower layer 16, away from the first dielectric bar 28.

 The second dielectric bar 72 is thus formed in the lower layer 16, in particular away from the first dielectric bar 28.

 The second dielectric bar 72 is formed in the central sub-layer 26B of the lower layer 16 and is delimited by a portion of the electrically conductive lower sublayer 24B of the lower layer 16 and laterally between two lower lateral boundaries 82.

 The second dielectric bar 72 opens on the cavity 32.

 As illustrated in FIG. 15, the second dielectric bar 72 has a surface 84 delimiting the cavity 32.

 The second dielectric bar 72 is disposed between a plane defined by a lower surface 21 C of the central layer 18 and a plane defined by a lower surface 21 B of the lower layer 16.

 The lower layer 16 is devoid of upper sub-layer 22B, in at least a portion of the lower layer 16 between the two lower lateral boundaries 82. In particular, in the example illustrated in FIG. 15, the lower layer 16 is entirely devoid of upper sub-layer 22B between the two lower lateral boundaries 82.

The second dielectric bar 72 disposed in the propagation zone 19, such that, in projection on the upper surface 20B of the lower layer 16, said second dielectric bar 72 is away from the lateral edges 36 of the cavity 32. As in the ninth component 101, the propagation zone 19 is delimited by a portion of the electrically conductive lower sublayer 24A of the upper layer 14, a portion of the upper sublayer 22A electrically conductive of the upper layer 14 and the boundaries upper side 78 joining said parts. The propagation zone 19 is also delimited laterally by the two central lateral boundaries 30 each arranged in the central layer 18 and spaced apart from each other.

 In addition, in the tenth component 10J, the propagation zone 19 is delimited by the portion of the electrically conductive lower sublayer 24B of the lower layer 16 extending below the second dielectric bar 72, by a portion of the upper sub-layer 22B electrically conductive bottom layer 16, and by the lower side boundaries 82, the lower side boundaries 82 joining said parts.

 The lower lateral boundaries 82 of the propagation zone 19 are able to prevent the passage of an electromagnetic wave having a wavelength greater than or equal to the predetermined minimum wavelength.

 The lower lateral boundaries 82 are each arranged in the lower layer 16.

 The lower lateral boundaries 82 extend parallel to the axis of propagation X-X and are here parallel to each other.

 They extend in particular over the entire thickness of the lower layer 16.

 The lower lateral boundaries 82 are spaced apart from each other.

 They are here in particular symmetrical to each other with respect to the median plane of the lateral edges 36. The second dielectric bar 72 is here centered on the median plane of the lateral edges 36.

 A cross section of the propagation zone 19 has substantially a cross shape.

 In particular, the lower lateral boundaries 82 extend for example here respectively in the extension of the upper lateral boundaries 78.

 In addition, in the example illustrated in FIG. 15, in projection on the upper surface 20B of the lower layer 16, the lower lateral boundaries 82 are disposed apart and between the lateral edges 36.

Each lower lateral boundary 82 electrically connects the upper sub-layer 22B of the lower layer 16 and the lower sub-layer 24B of the lower layer 16 between them. The lower lateral boundaries 82, the upper lateral boundaries 78 and the central lateral boundaries 30 electrically connect the lower sub-layer 24B of the lower layer 16 to the upper sub-layer 22A of the upper layer 14 respectively on either side of the the cavity 32.

 In the embodiment of FIG. 15, each lower lateral border 82 comprises a row of electrically conductive vias 34, arranged through the lower layer 16. More specifically, each via 34 extends in the ZZ direction, crossing the layer lower 16.

 Each via 34 electrically connects the upper sub-layer 22B of the lower layer 16 and the lower sub-layer 24B of the lower layer 16 between them.

 The distance between two successive vias 34 of a lower lateral border 82 is less than the predetermined minimum wavelength, in particular less than one-tenth of the predetermined minimum wavelength, preferably less than one twentieth of the length of the wavelength. predetermined minimum wave.

 A tenth method relating to the manufacture of the tenth component 10J will now be described.

 The tenth method differs from the ninth method in that the described embodiment step of the dielectric bar 28 corresponds to the production of the first dielectric bar 28.

 In the tenth method, the step of supplying the lower layer 16 comprises the production of the second dielectric bar 72.

 The supply of the lower layer 16 comprises the provision of a lower initial layer, the lower initial layer being intended to form the lower layer 16.

 The lower initial layer thus comprises at least one initial dielectric underlayer, intended to form the central sub-layer 26B of the lower layer 16, an electrically conductive upper sub-layer, intended to form the upper sublayer 22B of the layer lower 16, and an electrically conductive lower sublayer for forming the lower sub-layer 24B of the lower layer 16.

The realization of the second dielectric bar 72 includes the implementation of the lower lateral boundaries 82 and the removal of at least a portion, preferably all, of the electrically conductive upper sub-layer of the lower initial layer extending between the two lower lateral boundaries 82. The portion of the central dielectric sub-layer of the lower initial layer delimited between the lower lateral boundaries 82 forms said second dielectric bar 72.

 At the end of the step of producing the second dielectric bar 72, the lower initial layer forms the lower layer 16.

 During assembly, the central layer 18 is fixed to the lower layer 16 and the upper layer 14 is fixed to the central layer 18 to form the tenth component 10J.

 Thus, after assembly, the propagation zone 19 comprises a second dielectric bar 72 delimited in the lower layer 16, the second dielectric bar 72 being away from the first dielectric bar 28.

 As a variant of the tenth component 10J, the second dielectric bar 72 is not centered on the median plane of the lateral edges 36. In particular, the second dielectric bar 72 is laterally offset from the median plane of the lateral edges 36.

 The lower lateral boundaries 82 are then devoid of symmetry with respect to the median plane of the lateral edges 36.

 An eleventh component 10K according to the invention will now be described with reference to FIG.

 The eleventh component 10K differs from the ninth component 101 in that said dielectric bar 28 is a first dielectric bar 28.

 The waveguide 12 further comprises a second dielectric bar 72 disposed in the propagation zone 19 and delimited in the upper layer 14, away from the first dielectric bar 28.

 The second dielectric bar 72 is thus formed in the upper layer 14, in particular away from the first dielectric bar 28.

 The first dielectric bar 28 and the second dielectric bar 72 are each formed in the central sub-layer 26A of the upper layer 14 and are respectively defined by a portion of the upper sub-layer 22A electrically conductive of the upper layer 14 and laterally between an inner upper lateral border 86 and an outer upper lateral boundary 88.

 The first dielectric bar 28 and the second dielectric bar 72 each open at least partly on the cavity 32.

 As illustrated in FIG. 16, the first dielectric bar 28 and the second dielectric bar 72 each have a surface 90A, 90B delimiting the cavity 32.

Between an inner upper lateral boundary 86 and the outer upper lateral boundary 88 adjacent thereto, the upper layer 14 is devoid of lower sub-layer 24A, in at least a portion of the upper layer 14. By "an inner upper lateral and an adjacent outer upper lateral boundary" is meant that no inner upper lateral boundary 86 is interposed between said boundaries .

 As in the first component 10A, the propagation zone 19 is delimited by the upper electrically conductive sub-layer 22B of the lower layer 16 and the two central lateral boundaries 30 each arranged in the central layer 18 and spaced apart from one another. other.

 In addition, in the eleventh component 10K, the propagation zone 19 is delimited by the portion of the upper sub-layer 22A of the upper layer 14 extending above the first dielectric bar 28 and the second dielectric bar 72, by a portion of the electrically conductive bottom sublayer 24A of the top layer 14, and the inner upper side boundaries 86 and the outer upper side boundaries 88, the inner upper 86 and outer side boundaries 88 joining said portions.

 The inner upper 86 and outer 88 lateral boundaries are adapted to prevent the passage of an electromagnetic wave having a wavelength greater than or equal to the predetermined minimum wavelength.

 The upper internal lateral 86 and outer 88 boundaries are each arranged in the upper layer 14.

 The inner upper 86 and outer 88 lateral boundaries extend parallel to the X-X propagation axis and are here parallel to each other.

 They extend in particular over the entire thickness of the upper layer 14.

The inner upper 86 and outer 88 lateral boundaries are spaced from each other.

 The upper internal 86 and outer 88 lateral boundaries electrically connect the lower sub-layer 24A of the upper layer 14 and the upper sub-layer 22A of the upper layer 14 respectively.

 The outer upper lateral boundaries 88 and the central lateral boundaries 30 electrically connect the upper sub-layer 22B of the lower layer 16 to the upper sub-layer 22A of the upper layer 14, respectively on either side of the cavity 32.

In the example illustrated in FIG. 16, the outer upper lateral boundaries 88 are respectively arranged in the extension of the central lateral borders 30. In a variant, they are laterally offset with respect to the central lateral boundaries 30. The outer upper lateral boundaries 88 are here symmetrical to each other with respect to the median plane of the lateral edges 36.

 The inner upper lateral boundaries 86 are disposed between the outer upper lateral boundaries 88.

 The inner upper lateral boundaries 86 are here symmetrical to each other with respect to the median plane of the lateral edges 36.

 The first dielectric bar 28 and the second dielectric bar 72 are each laterally offset from the median plane of the lateral edges 36.

 In the example illustrated in FIG. 16, in projection on the upper surface 20B of the lower layer 16, the inner upper lateral boundaries 86 are disposed apart and between the lateral edges 36.

 The lower sub-layer 24A of the upper layer 14 electrically connects the inner upper lateral boundaries 86 to each other.

 Between the inner upper lateral boundaries 86, the lower sub-layer 24A of the upper layer 14 is continuous. By "continuous" is meant that the lower sub-layer 24A of the upper layer 14 is devoid of through opening.

 In the embodiment of FIG. 16, each of the inner and outer upper lateral boundaries 86 comprises a row of electrically conductive vias 34 formed through the top layer 14. More precisely, each via extends in the ZZ direction, crossing the upper layer 14.

 Each via electrically connects the lower sub-layer 24A of the upper layer 14 and the upper sub-layer 22A of the upper layer 14 between them.

 The spacing between two successive vias 34 of an upper internal lateral 86 or outer 88 border is less than the predetermined minimum wavelength, in particular less than one tenth of the predetermined minimum wavelength, preferably less than one twentieth the predetermined minimum wavelength.

 An eleventh method relating to the manufacture of the eleventh component 10K will now be described.

 The eleventh method differs from the ninth method in that the step of providing the upper layer 14 comprises the production of the first dielectric bar 28 and the production of the second dielectric bar 72.

The realization step comprises the implementation of the upper internal 86 and outer 88 lateral boundaries in the upper layer 14, and the removal of at least a portion of the electrically lower sub-layer. conductor of the upper initial layer extending between the inner upper 86 and outer 88 lateral boundaries adjacent to each other.

 The portions of the dielectric central sub-layer of the upper initial layer delimited between the inner upper 86 and outer 88 outer lateral boundaries form the first dielectric bar 28 and the second dielectric bar 72.

 A twelfth component 10L according to the invention will now be described with reference to FIG. 17.

 The twelfth component 10L differs from the eleventh component 10K in that the waveguide 12 further comprises another dielectric bar 28, said other dielectric bar 28 being disposed in the cavity 32, away from the lateral edges 36 of the cavity 32.

 Said other dielectric bar 28 is similar to the dielectric bar of the first component 10A.

 The twelfth component 10L makes it possible to enlarge the monomode band and also to obtain propagation characteristics of interest for the radiofrequency domain of application.

 A twelfth process relating to the manufacture of the twelfth component 10L will now be described.

 The twelfth method differs from the eleventh method in that it further comprises a step of producing the other dielectric bar 28.

 This step of producing the other dielectric bar 28 is substantially similar to the step of producing the dielectric bar of the first method.

 The embodiments described above can be combined in any technically possible combination.

Claims

1. Microwave component (10) comprising a waveguide (12) comprising at least one upper layer (14) having at least one electrically conductive surface, a lower layer (16) having at least one electrically conductive surface, and a central layer (18) interposed between the upper layer (14) and the lower layer (16), said layers defining a propagation zone (19) of an electromagnetic wave,  the propagation zone (19) extending along an axis of propagation, and comprising a cavity (32), the cavity (32) being delimited by the upper layer (14), by the lower layer (16), and, laterally, by two opposite lateral edges (36) of the central layer (18),  characterized in that the waveguide (12) comprises at least one dielectric bar (28) disposed in the propagation zone (19), the dielectric bar (28) being delimited in one of the upper layer (14) and the lower layer (16) or being disposed in the cavity (32) away from the side edges (36) of the cavity (32).  2. Component according to claim 1, wherein the dielectric bar (28) extends in a longitudinal direction parallel to the axis of propagation, and is centered on a median plane of the two lateral edges (36) or is shifted laterally. of the median plane of the two lateral edges (36).  3. Component according to any one of claims 1 or 2, wherein said dielectric bar (28) is disposed in the cavity (32) away from the side edges (36) of the cavity (32), the guide waveguide (12) comprising a functional fastening component (58), the functional fastening component (58) being formed by a plurality of dielectric fasteners (56) integral with the dielectric bar (28), each dielectric fastener (56) extending from one of the side edges (36), the dielectric fasteners (56) being configured to perform a filter function for an electromagnetic wave propagating in the propagation zone (19).  The component of claim 3, wherein each dielectric fastener (56) has a straight bar shape and extends from one of the side edges. 5. Component according to any one of claims 1 to 4, wherein said dielectric bar (28) is disposed in the cavity (32) away from the side edges (36) of the cavity (32), the layer core (18) comprising at least one dielectric underlayer (26C), the cavity (32) being delimited along the axis of propagation between a front end (60) and a rear end (62) of the core layer (18) , the bar dielectric (28) extending from the front end (60) to the rear end (62) and integral with said dielectric underlayer (26C) of the core layer (18).  6. Component according to any one of claims 1 to 5, wherein said dielectric bar (28) is disposed in the cavity (32) away from the side edges (36) of the cavity (32), said bar dielectric (28) being a first dielectric bar (28), the waveguide (12) further comprising a second dielectric bar (72), the second dielectric bar (72) being disposed in the cavity (32), away from said first dielectric bar (28), and away from the side edges (36) of the cavity (32).  7. Component according to any one of claims 1 or 2, wherein the dielectric bar (28) is delimited in one of the upper layer (14) and the lower layer (16), said dielectric bar (28). ) having a surface (80, 84, 90A, 90B) delimiting the cavity (32).  8. Component according to claim 7, wherein said dielectric bar (28) is a first dielectric bar (28), the waveguide (12) further comprising a second dielectric bar (72) disposed in the propagation zone. (19), the second dielectric bar (72) being delimited in one of the upper layer (14) and the lower layer (16), away from the first dielectric bar (28), and having a surface ( 80, 84, 90A, 90B) delimiting the cavity (32).  9. Component according to any one of claims 7 or 8, wherein the waveguide (12) further comprises another dielectric bar (28), said other dielectric bar (28) being disposed in the cavity (32). ), away from the side edges (36) of the cavity (32).  10. Component according to any one of claims 1 to 9, wherein the cavity (32) is filled with a fluid having a dielectric constant, or defines a sealed closed volume and is empty of fluid.  1. A method of manufacturing a microwave component comprising the following steps:  providing an upper layer (14) and a lower layer (16) respectively having at least one electrically conductive surface;  providing a central layer having one or a plurality of recesses, said recess (44) or said plurality of recesses (44) being adapted to form a cavity (32) delimited laterally by edges opposing sides (36) formed by the core layer (18); then, - assembling the layers so that the central layer (18) is interposed between the upper layer (14) and the lower layer (16), the layers defining a propagation zone (19) of an electromagnetic wave, the zone of propagation device (19) extending along an axis of propagation and comprising a cavity (32), the cavity (32) being formed by said recess (44) or said plurality of recesses (44) being delimited by the upper layer (14), by the lower layer (16), and laterally, by said side edges (36) of the core layer (18);  the step of supplying at least one of the layers (14, 16, 18) comprising the production of a dielectric bar (28), said dielectric bar (28) being arranged or intended to be arranged in said layer (14, 16, 18), so that after the assembling step, the dielectric bar (28) is arranged in the propagation zone (19) and is delimited in one of the upper layer (14) and the lower layer (16), or so that after the assembly step, the dielectric bar (28) is disposed in the propagation zone (19) and in the cavity (32) away from the edges lateral (36) of the cavity (32).  12. The method of claim 1 1, wherein the step of providing the central layer (18) comprises the realization of the dielectric bar (28), said dielectric bar (28) being arranged or intended to be disposed in said central layer (18), such that after the assembly step, the dielectric bar (28) is disposed in the propagation zone (19) and in the cavity (32) away from the lateral edges ( 36) of the cavity (32),  the dielectric bar (28) being intended to be disposed between a plane defined by an upper surface (20C) of the central layer (18) and a plane defined by a lower surface (21C) of the central layer (18).  The method of claim 12, wherein the step of providing the core layer (18) comprises:  the provision of an initial layer (46), the initial layer (46) being intended to form the central layer (18), comprising at least one initial dielectric underlayer (48) and being devoid of recess,  - cutting, in the initial layer (46), said plurality of recesses (44) for forming the cavity (32),  the step of producing the dielectric bar (28) being implemented during the cutting of said plurality of recesses (44), said plurality of cutout recesses (44) delimiting said dielectric bar (28), the dielectric bar ( 28) having a length, taken along the axis of propagation, equal to the length of the cavity (32), taken along the axis of propagation. The method of claim 12, wherein the step of providing the core layer (18) comprises: the provision of an initial layer (46), the initial layer (46) being intended to form the central layer (18), comprising at least one initial dielectric underlayer (48) and being devoid of recess,  - cutting, in the initial layer (46), said plurality of recesses (44) for forming the cavity (32),  the step of producing the dielectric bar (28) being implemented during the cutting of said plurality of recesses (44), said plurality of recesses (44) cut away being intended to delimit the cavity (32), and delimiting the dielectric bar (28) and means (54) for attaching the dielectric bar (28),  the fastening means (54) comprising a plurality of dielectric fasteners (56) connecting the dielectric bar (28) to at least one of the side edges (36).  15. A process according to claim 12, wherein the step of producing the dielectric bar (28) comprises providing a dielectric bar (28) and means (54) for attaching the dielectric bar (28), fastening means (54) comprising a plurality of dielectric fasteners (56) integral with said dielectric bar (28), the dielectric bar (28) and the fastening means (54) being provided away from the core layer (18).  16. A method according to any one of claims 14 or 15, wherein the step of assembling the layers comprises fixing the central layer (18) to the lower layer (16), then removing the means of fastener (54), by their cutting, once the central layer (18) attached to the lower layer (16).  17. The method of claim 1 1, wherein the step of providing one of the upper layer (14) and the lower layer (16) comprises the realization of the dielectric bar (28), said dielectric bar ( 28) being arranged or intended to be disposed in said layer (14, 16), so that after the assembly step, the dielectric bar (28) is disposed in the propagation zone (19) and is delimited in said layer (14, 16).