RU2743070C1 - Waveguide with coplanar waveguide transmission line - Google Patents

Abstract

FIELD: radio engineering.SUBSTANCE: invention relates to radio engineering. The waveguide with a coplanar waveguide transmission line comprises a rectangular insulator substrate with a layer of metallization of all the surfaces thereof and with a conductor arranged in width on the upper layer thereof in the centre, gaps formed in the upper layer of the rectangular insulator substrate on both sides of the conductor, through vertical metallized transition openings to suppress parasitic modes along the conductor designed on two sides of the upper layer of the insulator substrate and located aside the gaps in at least three rows mirrored to each other. The metallized transition openings in each row are offset relative to the metallized transition openings in the adjacent row by a value equal to half the diameter of the metallized transition openings.EFFECT: technical result consists in increase in the operating range of the microwave device, the provision of ultra-broadband operating mode, a high degree of integration, a high level of coordination, and low losses at high frequencies.1 cl, 6 dwg

Description

The invention relates to radio engineering, and, more specifically, to a waveguide with pin walls of a coplanar-waveguide matching transmission line, implemented in printed circuit boards.

BACKGROUND OF THE INVENTION Current trends in communication technology require devices that operate in a wide bandwidth in the millimeter wavelength range. Currently, one of the known technologies is SIW structures (integrated printed waveguide with pin walls), which play an important role, since they have a number of advantages such as simplicity of design and manufacture, low losses and complete shielding in the millimeter range.

For example, the patent for invention RU 2665335 C1 describes the possibility of introducing a controlled switch into an SIW structure containing a printed circuit board with an upper and a lower metallization layer and a dielectric layer between them, waveguide walls formed by two rows of metallized vias electrically connected to conductive layers , and adjacent holes in a row are located from each arc at a distance of less than one tenth of the wavelength propagating in the waveguide, and the distance between the rows is more than half the wavelength.

Despite all the advantages, the controllable switch built into the SIW structure has several disadvantages, such as:

- limited frequency range, which is determined by the cross-section of the structure geometry based on the relationship with the wavelength and the absence of an additional row of plated holes. The geometry of the structure means the section of the waveguide formed by the distance between the walls of two rows of plated holes.

- the technological complexity of integrating the currently available switching components and surface-mounted elements into SIW structures, which increases the final cost of mm-range products.

The claimed invention has a number of differences from the invention described above, built into the waveguide structure of a coplanar line, a different principle of distribution of holes in the structure (adjacent holes in the series of invention RU 2665335 C1 are located from each arc at a distance of less than one tenth of the wavelength propagating in the waveguide, and the distance between the rows is more than half the wavelength, and in our patentable invention, through vertical vias of metallized holes made on both sides of the upper layer of the dielectric substrate and located on the side of the gaps in at least three rows are mirrored to each other, and the vias in each row are displaced relative to the vias of the adjacent row by an amount equal to half the diameter of the vias of the metallized holes), by the presence of an additional third row of holes.

The aim of the claimed invention is to expand the operating range of microwave devices and reduce the cost of products in the prior art, and is formed by the need to create a waveguide with a corresponding transmission line that satisfies the following conditions:

- ultra-wideband operation mode,

- ensuring a high degree of integration on an affordable element base (microcircuits, crystals),

- ensuring a high level of matching between microwave elements,

- low manufacturing cost when using classic PCB technologies.

- low losses at high frequencies up to 100 GHz.

At the moment, known technologies do not allow simultaneous fulfillment of all of the above conditions when developing microwave devices operating in the ultra-wideband frequency range.

In order to expand the capabilities of the prior art, the present invention is directed to a coplanar-waveguide matching line waveguide providing ultra-wideband operation, high matching between microwave elements and low losses at high frequencies up to 100 GHz.

The technical result of the claimed invention is to provide an ultra-wideband mode of operation, a high level of matching between microwave elements and low losses at high frequencies up to 100 GHz

The essence of the invention

According to the present invention, there is proposed a waveguide with a coplanar-waveguide matching line (KWSL), including a rectangular dielectric substrate, with a metallization layer of all its surfaces and with a conductor placed in width on its upper layer in the center, gaps made in the upper layer of a rectangular dielectric substrate, with on both sides of the conductor, through vertical plated vias for suppression of parasitic modes along the conductor, made on both sides of the upper layer of the dielectric substrate and located on the side of the gaps in at least three rows mirrored with respect to each other on both sides, with plated vias in each row is displaced relative to the vias of the adjacent row by an amount equal to half the diameter of the vias of the adjacent row.

In a second embodiment, the Coplanar Waveguide Matching (CCL) waveguide further comprises an upper dielectric layer with a conductive metal layer that is electrically connected to vertical vias to suppress parasitic modes along the conductor.

An example of the implementation of the claimed device.

A waveguide with a coplanar-waveguide matching line (KVSL), including a 0.127 mm thick dielectric substrate on Rogers RT / duroid 5880, with a metallization layer of all its surfaces and with a 0.36 mm wide central conductor placed on its upper layer, made with a gap of 0.2 mm relative to the sides metallization, characterized in that in each of the sides to suppress parasitic modes along the central conductor, a system of through vertical holes with a diameter of 0.2 mm is made, forming side walls, consisting of at least three rows, each of which is displaced relative to the next row by 0.1 mm, at this hole is also metallized. The system of plated through holes allows keeping the field in a certain volume. The geometric dimensions of the line are designed for a characteristic impedance of 50 Ohm, which allows it to match high-frequency connectors and any surface mount elements.

Rogers RT / duroid 5880 is a glass fiber reinforced PTFE composite.

Such a material has ideally low moisture absorption characteristics and is ideal for applications in high humidity conditions.

Description of drawings

In fig. 1 illustrates the claimed waveguide with a coplanar-waveguide matching line (CFWL).

In fig. 2 illustrates a graph showing the results of line measurements from 0.01 GHz to 100 GHz with a length of 3 cm with two 2492-04-6 connectors.

The graph shows the following: the level of direct losses in the range of 0.01-100 GHz is 5 dB. In the 26-30 GHz range, the direct loss level is 1.8 dB. The patent for the switch RU 2665335 C1 shows a graph of the dependence of direct losses S (1.2) on frequency in the range 26-32 GHz with a direct loss of 5 dB. FIG. 3 indicates pos. 1 and 2 show the arrangement of the layers of Rodgers 4003 and Rodgers 4450 with thicknesses of 0.203 mm and 0.203 mm, respectively.

FIG. 4 shows a second embodiment of a coplanar-waveguide matching line waveguide with the following reference numerals:

3 - KVSL conductor.

4 - the gap between the central conductor and the metallization bead.

5 - the distance between the centers of the plated holes.

6 - the diameter of the plated holes.

7 is the distance from the top wall to the coplanar line conductor.

8 - height of the waveguide with the coplanar-waveguide matching line according to the second embodiment.

FIG. 5 shows a graph of the ratio of the calculated parameters, the calculated parameters S (1.1) up to 40 GHz of the segment according to the second embodiment of the waveguide with a coplanar-waveguide matching line with a length of 28 mm up to 40 GHz.

It can be seen from the graph that in the range up to 40 GHz, the calculated return loss level is less than 40 dB.

FIG. 6 shows a graph of the ratio of the calculated parameters, the calculated parameters S (1.2) up to 40 GHz of the segment according to the second embodiment of the waveguide with a coplanar-waveguide matching line with a length of 28 mm up to 40 GHz.

The graph shows that the level of direct losses in the range up to 40 GHz is 0.7 dB.

Rodgers 4003 is a heat-resistant ceramic-filled material reinforced with glass fiber. Features and benefits of such materials:

- They do not contain fluoroplastic. Processing technology is the same as FR4

- Ultra-low flammability (RO 4350 TM) Lower handling and assembly costs

- Excellent high frequency performance due to low dielectric constant and low loss

- Optimal for devices with higher operating frequencies

- Stable electrical properties over a wide frequency range

- Optimal for multilayer and mixed dielectric boards

- Low value of thermal coefficient of dielectric constant

- Optimal for temperature sensitive circuits

- Low stretch along the Z axis

- Guaranteed high quality plated holes

- Exceptional reliability of surface mount assemblies

-Suitable for use in hybrid MPPs with epoxy fiberglass

- High glass transition temperature (280 C)

- No deformation during brazing assembly. High reliability of plated holes.

Rodgers 4003 has the same characteristics as Rodgers 4003 only in addition to this it is also a refractory material.

Claims (2)

1. A waveguide with a coplanar-waveguide matching line, including a rectangular dielectric substrate with a metallization layer of all its surfaces and with a conductor located in width on its upper layer in the center, gaps made in the upper layer of a rectangular dielectric substrate, on both sides of the conductor, through vertical vias for the suppression of parasitic modes along the conductor, made on both sides of the upper layer of the dielectric substrate and located on the side of the gaps in at least three rows mirrored to each other on both sides, and the vias in each row are offset relative to the transition metallized holes of the adjacent row by an amount equal to half the diameter of the metalized vias. 2. A waveguide with a coplanar-waveguide matching line according to claim 1, characterized in that it further comprises an upper dielectric layer with a conductive metal layer, which is electrically connected to through vertical vias for suppression of parasitic modes along the conductor.

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