JP2016225801A - Waveguide microstrip line converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a waveguide microstrip line converter of low conversion loss, capable of increasing the bandwidth without relying upon the manufacturing variation.SOLUTION: A waveguide microstrip line converter 100 includes: a square waveguide 10 having a short circuit surface at one end and a window 13 in the side perpendicular to the short circuit surface, and an opening 14 at the other end; and a microstrip wiring board 20 consisting of a dielectric substrate 21 including a microstrip line 22MC having one end inserted from the window 13 of the square waveguide 10, and including the microstrip line 22MC on principal surface perpendicular to the short circuit surface. The microstrip line 22MC is connected with a probe conductor 22P via a strip conductor 22C narrower than the microstrip line 22MC in the square waveguide 10. The dielectric substrate 21 is mounted on a support which can adjust the length and position in the square waveguide 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a waveguide microstrip line converter having a structure capable of compensating for manufacturing variations.

  A conventional waveguide microstrip line converter is configured by inserting a dielectric substrate through a window provided on the side surface of the waveguide at a distance that is approximately ¼ of the in-tube wavelength from the waveguide short-circuit surface. In the conventional waveguide microstrip line converter, the loss is obtained by adjusting the pattern shape of the probe conductor on the dielectric substrate or the protruding amount of the probe conductor from the window to match the impedance of the waveguide and the microstrip line. Suppresses the transmission of microwave signals. At that time, it is important to suppress the spatial radiation from the window provided in the waveguide and to improve the mounting accuracy of the dielectric substrate with respect to manufacturing and assembly variations.

  Therefore, for example, in the waveguide microstrip line converter disclosed in Patent Document 1, a dielectric substrate is inserted into a window provided at a distance of ¼ wavelength from the short-circuit surface of the waveguide. A groove is provided in the housing, and a dielectric substrate is fitted in the groove. In addition, a microstrip line and a probe conductor for microwave signal excitation are provided on the dielectric substrate, and impedance matching between the waveguide and the microstrip line is possible by changing the amount of insertion of the dielectric substrate. It becomes. The above structure is a simple structure. Since the microstrip line and the probe conductor are formed in the longitudinal direction of the dielectric substrate, the width of the dielectric substrate is reduced and the window is also reduced in size. Therefore, not only can the spatial radiation of the microwave signal be reduced, but also the influence on the reflection characteristics can be reduced, and the microwave signal can be transmitted efficiently by reducing the passage loss, and further, the risk of oscillation due to spatial resonance can be reduced. However, since the waveguide and the microstrip line are matched only by the protruding amount of the dielectric substrate and the probe conductor, the impedance locus that changes with the frequency change is unidirectional from low frequency to high frequency, and the reflection characteristics are narrow band It becomes. That is, there has been a problem that the loss of the microwave signal is increased because the amount of insertion of the dielectric substrate or the distance from the short-circuit plane is changed minutely due to manufacturing and assembly variations, leading to deterioration of reflection characteristics. The problem becomes more pronounced as the frequency increases.

  In view of this, a structure has been proposed in which a waveguide microstrip line converter that is resistant to manufacturing and assembly variations by widening the reflection characteristics is provided. Consider a case where a microwave signal is input from an opening of a waveguide of a waveguide microstrip line converter. The microwave signal is excited by a probe conductor on a dielectric substrate inserted in a window provided at a distance of about ¼ wavelength from the short-circuit surface of the waveguide. The impedance between the waveguide and the microstrip line on the dielectric substrate is matched by adjusting the amount of insertion and the probe conductor of a substantially cross shape. The probe conductor rotates the impedance locus once around the center, so that a frequency resonance point can be created and the reflection characteristics can be broadened. Thereby, it became a structure strong against manufacturing assembly variation.

Japanese Patent Laid-Open No. 5-90806

  However, since the substantially cross-shaped probe conductor can be extended only in the direction perpendicular to the longitudinal direction of the dielectric substrate, the window is enlarged. As the window becomes larger, the microwave signal in the waveguide is radiated into the space, which not only affects the reflection characteristics but also increases the microwave signal loss. The risk of oscillation due to spatial resonance has also increased. In addition, although it is possible to broaden the bandwidth, the dielectric substrate is generally attached to the housing with a conductive adhesive or soldering, so the desired characteristics cannot be obtained due to the attachment state or manufacturing variation, It may be necessary to replace the microstrip wiring board. Furthermore, pattern damage may occur in adjustment processes such as testing and measurement, and the dielectric substrate may need to be replaced. When it is necessary to replace the dielectric substrate, complicated additional steps such as a step of peeling the dielectric substrate and a step of cleaning the casing after peeling are required, resulting in a large process return. It was.

  In view of the above, there has been a demand for a waveguide microstrip line converter that has a large allowable range for manufacturing variations, can easily compensate for manufacturing variations, can be widened, and has good reflection characteristics.

  The present invention has been made in view of the above, and an object of the present invention is to obtain a waveguide microstrip line converter that can be broadened without depending on manufacturing variations and has a small conversion loss.

  In order to solve the above-described problems and achieve the object, the waveguide microstrip line converter of the present invention has a short-circuited surface at one end and a window on a side surface orthogonal to the short-circuited surface, and an opening at the other end. And a microstrip wiring substrate made of a dielectric substrate having a microstrip line on the main surface orthogonal to the short-circuited surface, one end of which is inserted from the waveguide window. The microstrip line is connected to the probe conductor via a strip conductor narrower than the microstrip line in the waveguide. The dielectric substrate is placed on a support whose length and position in the waveguide can be adjusted, and an electromagnetic wave propagating in the waveguide and an electric signal transmitted on the microstrip line on the probe conductor. And interconvert.

  According to this configuration, there is an effect that it is possible to obtain a waveguide microstrip line converter capable of widening the band and having a small conversion loss without depending on manufacturing variations.

The perspective view which shows the waveguide microstrip line converter which concerns on Embodiment 1. FIG. The principal part enlarged view which shows the waveguide microstrip line converter which concerns on Embodiment 1. FIG. The principal part expanded sectional view which shows the waveguide microstrip line converter which concerns on Embodiment 1. FIG. The principal part expansion perspective view which shows the waveguide microstrip line converter which concerns on Embodiment 1. FIG. Top view of microstrip wiring board of waveguide microstrip line converter according to Embodiment 1 It is a figure which shows the cross section of the microstrip wiring board of the waveguide microstrip line converter which concerns on Embodiment 1, and is AA sectional drawing of FIG. Sectional drawing which faces the window of the rectangular waveguide of the waveguide microstrip line converter concerning Embodiment 1 The perspective view which shows the carrier carrying the microstrip wiring board of the waveguide microstrip line converter which concerns on Embodiment 1. FIG. It is a figure which shows the characteristic of the waveguide microstrip line converter of Embodiment 1 and a comparative example, (a) is a Smith chart, (b) is a figure which shows a reflection characteristic. The principal part enlarged view which shows the waveguide microstrip line converter which concerns on Embodiment 2. FIG. Top view of microstrip wiring board of waveguide microstrip line converter according to Embodiment 3

  Hereinafter, a waveguide microstrip line converter according to an embodiment of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment, In the range which does not deviate from the summary, it can change suitably. In the drawings shown below, the scale of each layer or each member may be different from the actual for easy understanding, and the same applies to the drawings. Further, even a cross-sectional view may not be hatched for easy viewing of the drawing.

Embodiment 1 FIG.
The waveguide microstrip line converter according to the first embodiment will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing a waveguide microstrip line converter according to Embodiment 1, FIG. 2 and FIG. 3 are enlarged sectional views of the principal part, and FIG. 4 is an enlarged perspective view of the principal part. FIG. 5 is a top view of the microstrip wiring board of the waveguide microstrip line converter according to Embodiment 1, and FIG. 6 is a cross-sectional view taken along the line AA of FIG. 7 is a cross-sectional view of the waveguide microstrip line converter according to the first embodiment, which faces the rectangular waveguide window, and FIG. 8 is a diagram of the waveguide microstrip line converter according to the first embodiment. It is a perspective view which shows the carrier which mounts a microstrip wiring board. FIG. 2 is a cross-sectional view of the waveguide and the housing cut along a plane along the XY plane of FIG. FIG. 3 is a cross-sectional view of the waveguide and the housing cut along the opening 14 side in FIG. 1, that is, a plane along the XZ plane. FIG. 7 is a cross-sectional view of the waveguide cut along a plane along the YZ plane including the window of FIG.

The waveguide microstrip line converter 100 according to the first embodiment is a distance L that is about ¼ of the in-tube wavelength from the short-circuit surface 12 that is one end of the waveguide body 11 of the rectangular waveguide 10 as a waveguide. ₁ includes a microstrip wiring board 20 on which the center O of the probe conductor 22P is located. The waveguide body 11 constitutes a transmission tube having a rectangular cross section. The rectangular waveguide 10 has a window 13 on a side surface 11S orthogonal to the short-circuit surface 12, and an opening 14 at the other end. A wiring 22 is formed on the microstrip wiring substrate 20. The microstrip line 22MC constituting the wiring 22 is connected to the probe conductor 22P through the strip conductor 22C having a narrower width than the microstrip line 22MC in the rectangular waveguide 10. The dielectric substrate 21 is placed on a conductive carrier 30 as a support that can be adjusted in length and position in the rectangular waveguide 10. The dielectric substrate 21 is fixed in a state where the position is adjusted on the carrier 30 and impedance matching is achieved. The waveguide microstrip line converter 100 mutually converts an electromagnetic wave propagating in the rectangular waveguide 10 and an electric signal transmitted on the microstrip line 22MC on the probe conductor 22P of the microstrip wiring board 20. .

  The rectangular waveguide 10 has a window 13 on a side surface 11S orthogonal to the short-circuit surface 12, and an opening 14 at the other end. Further, the waveguide body 11 has a waveguide connection flange 15 for connecting to the connection destination waveguide at the opening 14. Furthermore, the waveguide body 11 has a housing connection flange 16 for connecting to the housing 40 in the window 13. The waveguide microstrip line converter 100 mutually converts an electromagnetic wave propagating in the rectangular waveguide 10 and an electric signal transmitted on the microstrip line 22MC on the probe conductor 22P of the microstrip wiring board 20. .

  As shown in FIGS. 3 and 4, the microstrip wiring board 20 is mounted on a conductive carrier 30, and is provided on the wall surface of the casing body 41 of the casing 40 by screws 33 from the through holes 32. It is fixed to the mounting hole 43 by screws. The carrier 30 has a carrier body 31 made of a metal plate, a pair of through holes 32 on both sides of the center of the carrier body 31, and a pair of positioning holes 34 on both sides of the through hole 32 at equal intervals. The screw 33 and the positioning pin 35 can be fixed to the housing main body 41 of the housing 40. The through hole 32 provided in the center of the carrier body 31 is a cross-shaped long hole, and the fixing position of the screw 33 can be changed in the XY direction within the through-hole 32 which is a cross-shaped long hole. Further, although the distance to the wall surface of the casing body 41 in the Z direction is within the range of depth fine adjustment depending on the tightening state of the screw 33, the position in the Z direction can be changed. If a number of thin sheets such as gold shims are stacked on the carrier body 31, the thickness can be increased and the adjustment in the Z direction is possible. The microstrip wiring board 20 is adhered to the carrier body 31 with a conductive adhesive. As a result, the center position and direction of the probe conductor 22P on the microstrip wiring board 20 can be adjusted, and the impedance matching shift due to manufacturing variations of the rectangular waveguide 10, the casing 40, or the microstrip wiring board 20 can be reduced. Can be compensated. The connection between the carrier body 31 and the microstrip wiring board 20 may be a conductive adhesive, but can also be made by solder.

  As shown in FIG. 3, the second main surface 20B, which is the back surface of the microstrip wiring substrate 20, is mounted on a conductive carrier 30, and is in close contact with the wall of the housing body 41 of the metal housing 40. Fixed. The probe conductor 22P provided on the first main surface 20A of the microstrip wiring board 20 is in the X, Y, and Z directions by the screw 33 and the positioning pin 35 provided on the carrier 30 so that the probe conductor 22P is at the optimum position. Can be adjusted.

  5 and 6, the microstrip wiring substrate 20 includes a dielectric substrate 21, a microstrip line 22MC formed on the first main surface 21 of the dielectric substrate, a strip conductor 22C, and a square probe. The conductor 22P is continuously arranged on a straight line. The probe conductor 22P on the dielectric substrate 21 is connected to the microstrip line 22MC in the rectangular waveguide 10 via the strip conductor 22C having a width smaller than that of the microstrip line 22MC. In the dielectric substrate 21, a solid ground conductor layer 22G is formed on the second main surface 21B facing the formation region of the strip conductor 22C and the microstrip line 22MC, except for the region facing the probe conductor 22P. . The microstrip wiring board 20 couples the electric field of the electromagnetic wave propagating in the rectangular waveguide 10 on the probe conductor 22P, and generates an electromagnetic wave-electric signal between the electric signal transmitted on the microstrip line 22MC. Perform mutual conversion. In the first embodiment, the probe conductor is a square. However, the probe conductor is not limited to a square and may be a quadrangle.

As shown in FIG. 7, the microstrip wiring board 20 is inserted into the waveguide through a window 13 provided on the side wall of the rectangular waveguide 10, and the protruding amount is adjusted by adjusting the screw 33 of the carrier 30. Impedance matching is performed while adjusting. Reference position of the probe conductor 22P is the distance L ₁ away is about 1/4 wavelength of the guide wavelength from the short-circuit plane 12. That is, the distance L ₁ from the short-circuit surface 12 to the center line of the probe conductor 22P is ¼λ, and the adjustment is performed by adjusting the screw 33 to the protruding amount L ₂ and the inclination of the probe conductor 22P.

  Further, the rectangular waveguide 10 is fixed to the connection destination waveguide 10 </ b> S with a screw 15 </ b> N via a waveguide connection flange 15 provided in the opening 14. The rectangular waveguide 10 is fixed by a screw 16N and a connecting flange 42 provided on the casing body 41 of the casing 40 via the casing connecting flange 16 at the window 13.

  A microstrip line 22MC, a strip conductor 22C, and a probe conductor 22P are formed on the first main surface 21A of the dielectric substrate 21, and a ground conductor layer is entirely formed on the second main surface 21B that is the back surface. Although 22G is formed, the ground conductor layer 22G is not formed on the back side of the probe conductor 22P. By providing the narrow strip conductor 22C between the probe conductor 22P and the microstrip line 22MC, the probe conductor 22P and the narrow strip conductor 22C can be matched in the rectangular waveguide 10 in two steps. Impedance matching is realized. Due to the two-step matching between the probe conductor 22P and the narrow strip conductor 22C, the impedance locus makes one rotation near the center, so that a frequency resonance point can be created and the reflection characteristics can be broadened.

  In this structure, impedance adjustment can be performed without increasing the width of the dielectric substrate 21 as compared with the cross-shaped probe conductor, and there is no need to enlarge the window. There is no inconvenience that it affects. That is, like the waveguide microstrip line converter of Patent Document 1 in which the probe conductor is formed in a cross shape with respect to the microstrip line 22MC, the dielectric substrate is increased, and as a result, the window is enlarged, There is no fear that the electromagnetic wave signal in the rectangular waveguide 10 will radiate into space. Further, in the case of the waveguide microstrip line converter disclosed in Patent Document 1, the radiation of an electromagnetic wave signal into space not only affects the reflection characteristics but also increases the microwave signal loss. In addition, the waveguide microstrip line converter disclosed in Patent Document 1 has a problem that the risk of oscillation due to spatial resonance increases. On the other hand, the waveguide microstrip line converter 100 according to the first embodiment is advantageous in that it is small and has little loss.

  Further, although the microstrip wiring board 20 of the first embodiment can be widened, the absolute value of the impedance is large depending on the length or width of the narrow strip conductor 22C. Variations in length can lead to large changes in characteristic impedance. In this case, as will be described later, since the microstrip wiring board 20 can be easily adjusted in the XYZ directions on the carrier 30, it can be compensated by adjusting the position of the probe conductor 22P.

  In addition, since the position of the microstrip wiring board 20 on the carrier 30 can be easily adjusted in the XYZ directions and is detachable, the microstrip wiring board 20 can be easily replaced with a microstrip wiring board 20 having other characteristics. It has a structure that is resistant to variations. In addition, although the bandwidth can be increased, the absolute value of the impedance increases due to the length or width of the narrow strip conductor 22C, or the target characteristics cannot be obtained due to manufacturing variations. The microstrip wiring board 20 can be easily replaced. Furthermore, the microstrip wiring board 20 may cause pattern damage due to test adjustment, and the microstrip wiring board 20 may need to be replaced. When the microstrip wiring board 20 needs to be replaced, it can be easily replaced because it is detachably fixed by screwing rather than being fixed by a fixing member such as solder or adhesive.

  Next, the assembly process of the waveguide microstrip line converter according to the first embodiment will be briefly described. First, the microstrip wiring substrate 20 is formed. As shown in FIGS. 5 and 6, a glass epoxy substrate is used as the dielectric substrate 21, a copper foil is attached to both surfaces of the dielectric substrate 21, and the copper foil is patterned by photolithography. 20 is formed. On the first main surface 21A of the dielectric substrate 21, a microstrip line 22MC, a strip conductor 22C narrower than the microstrip line 22MC, and a probe conductor 22P are continuously formed on one straight line. . The second main surface 21B of the dielectric substrate 21 is covered with a ground conductor 22G except for a region facing the probe conductor 22P, which serves as a microwave antenna propagating through the rectangular waveguide 10. .

  The microstrip wiring board 20 is bonded to the carrier body 31 of the carrier 30 shown in FIG. 8 with a conductive adhesive.

  In this way, the carrier 30 on which the microstrip wiring board 20 is mounted is arranged on the wall surface of the housing 40 so that the probe conductor 22P protrudes from the window 13 of the rectangular waveguide 10, as shown in FIG.

  And as shown in FIG. 3, the positioning pin 35 is inserted and temporarily fixed so that it may penetrate the wall surface of the housing | casing 40 from two pairs of positioning holes 34 formed in the carrier 30. As shown in FIG. After that, the microstrip wiring board 20 is mounted by screwing a pair of screws 33 through the through hole 32 which is a long hole and screwing into a mounting hole 43 provided in the housing body 41 of the housing 40. The carrier 30 is fixed. The attachment hole 43 has a thread groove, and the carrier 30 is fixed to the housing body 41 by screwing the screw 33 into the thread groove. At this time, since the through hole 32 is a long hole, position adjustment in the XZ direction is possible. Further, the position in the Y direction can be adjusted by adjusting the screwing depth of the screw 33 into the mounting hole 43.

  At this time, by measuring the characteristic impedance, adjusting the position of the screw 33 in the XYZ direction along the through hole 32 which is a long hole, performing impedance matching, and screwing into the mounting hole 43 of the housing body 41, The carrier 30 is fixed to the housing body 41. In this way, the microstrip wiring board 20 is mounted on the housing 40. When impedance matching cannot be performed by position adjustment, another microstrip wiring board 20 is replaced with the carrier 30 and screwed again. Thus, a set of a plurality of microstrip wiring boards 20 and carriers 30 is prepared, and a set of the microstrip wiring boards 20 and carriers 30 within the impedance matching range is selected and fixed.

Next, the operation of the waveguide microstrip line converter according to Embodiment 1 assembled as described above will be described with reference to the drawings. Consider a case where a microwave signal is input from the connected waveguide 10S to the rectangular waveguide 10 of the waveguide microstrip line converter 100. Microwave signal inputted from the connection lead waveguide 10S is reflected rectangular waveguide 10 are as short surface 12, an electric field or magnetic field is concentrated at a distance L ₁ 1/4 guide wavelength from the short-circuit plane 12. The probe conductor 22P on the microstrip wiring board 20 inserted from the window 13 provided in the rectangular waveguide 10 at the location where the electric field or magnetic field is concentrated excites a microwave signal, passes through the strip conductor 22C, and then the microstrip line. A microwave signal is transmitted as a high-frequency signal to 22MC. Of course, the same principle applies when the signal is input from the microstrip line 22MC. The microwave signal input from the microstrip line 22MC is transmitted to the probe conductor 22P through the strip conductor 22C. The probe conductor 22P excites the microwave signal, and the rectangular waveguide 10 to the connection destination waveguide 10S. Is transmitted. Microwave signal is also at this time, is reflected by the short circuit surface 12, an electric field or magnetic field is concentrated at a distance L ₁ 1/4 guide wavelength from the short-circuit plane 12.

  In order to match the impedance between the microstrip line 22MC on the microstrip wiring board 20 and the rectangular waveguide 10, two-step matching is achieved by the probe conductor 22P and the strip conductor 22C. By changing the impedance stepwise, the microstrip wiring board 20 according to the first embodiment has a low-frequency to high-frequency impedance locus on the Smith chart as shown by a curve a in FIG. Can draw a circle near the center. For this reason, a frequency resonance point can be created, and the reflection characteristic can be broadened. As shown in FIG. 9B, the result of measuring the reflection characteristics with respect to the frequency shows that the ratio band, that is, the bandwidth with respect to the center frequency is 21.4% in the Ku band having the frequency of 12.9 to 18 GHz. The spec line SL is indicated by a broken line in FIG. The ratio band is the ratio of the bandwidth that falls within the range of the spec line SL to the center frequency.

  For comparison, a Smith chart in the case of a comparative microstrip substrate in which the probe conductor 22P is directly connected to the microstrip line 22MC without providing the strip conductor 22C is shown by a curve b in FIG. The locus of impedance is unidirectional from the low frequency to the high frequency as shown in the Smith chart by the curve b in FIG. 9A, and the reflection characteristic becomes a narrow band. FIG. 9B shows the reflection characteristic with respect to the frequency in the microstrip substrate of the comparative example with a curve b. The specific bandwidth was about 14.3%. The ratio band is the ratio of the bandwidth that falls within the range of the spec line SL to the center frequency. That is, there is a problem that the loss of the microwave signal increases because the insertion characteristic of the dielectric substrate or the distance from the short-circuit plane slightly changes due to manufacturing assembly variations, leading to deterioration of the reflection characteristics. The problem of increased loss becomes more pronounced as the frequency increases.

  From the comparison of the curve a and the curve b in FIG. 9B, the specific band of the waveguide microstrip line converter 100 of the first embodiment can be improved by about 7% by interposing the narrow strip conductor 22C. I understand.

  In addition, the microstrip wiring board 20 can reduce the window 13 of the rectangular waveguide 10 by narrowing the width to the end of the probe conductor 22P, thereby suppressing the spatial radiation of microwaves. The width of the window 13 can be reduced to half or less in the Ku band with respect to the waveguide microstrip line converter using the cross-shaped probe conductor used in Patent Document 1.

  Further, the carrier 30 is used to improve the positioning accuracy with respect to the protruding amount of the microstrip wiring substrate 20 to the rectangular waveguide 10 and the distance from the short-circuit surface 12 of the rectangular waveguide 10. The carrier 30 is provided with positioning pins 35 that are used only during manufacture, in addition to screws 33 that are fixed to the casing body 41 of the casing 40. The positioning pin 35 has a function of correcting a positional shift due to the tolerance of the screw 33.

  In addition, the connection between the dielectric substrate 21 of the microstrip wiring substrate 20 and the housing 40 is not glued or soldered but screwed, so that the structure can be easily replaced even when the microstrip wiring 20 is damaged. ing.

  With the configuration as described above, not only can the impedance between the rectangular waveguide 10 and the microstrip line 22MC be matched in a wide band, but also by providing a narrow strip conductor 22C as an impedance conversion mechanism in the longitudinal direction of the dielectric substrate 21. The spatial radiation of the microwave signal can be suppressed without enlarging the window 13 of the rectangular waveguide 10. Further, since the housing 40 and the dielectric substrate 21 of the microstrip wiring substrate 20 are screwed, replacement is easy when the dielectric substrate 21 is damaged, and positioning accuracy by the positioning pins 35 can be increased, resulting in manufacturing variations. A strong waveguide microstrip line converter can be realized.

  In the first embodiment, a glass epoxy substrate is used as the dielectric substrate, but another dielectric substrate such as a ceramic substrate may be used. When a ceramic substrate is used, a desired metal pattern is formed on the ceramic substrate surface by sputtering or strike plating, and then, for example, Ti (titanium), Pd (palladium), Cu (copper), ni (nickel) is formed on the metal pattern. By forming plating layers in the order of Au (gold), a highly accurate microstrip wiring board can be formed. In addition, after a metal layer is formed on the ceramic substrate surface by sputtering or strike plating, for example, Ti (titanium), Pd (palladium), Cu (copper), ni (nickel), Au (gold) are plated in this order on the metal layer. A highly accurate microstrip wiring substrate can also be formed by forming a layer and patterning by photolithography.

Embodiment 2. FIG.
As shown in FIG. 10, the waveguide microstrip line converter according to the second embodiment is connected between the rectangular waveguide 10 and the housing 40 by fixing the flange with screws. The housing connection flange 16 of the rectangular waveguide 10 and the connection flange 42 of the housing 40 are connected by a screw 16N. On the other hand, the waveguide connection flange 15 of the rectangular waveguide 10 and the connection destination waveguide flange 15S of the connection destination waveguide 10S are fixed with screws 15N. These connections are also constituted by the pins 15CP and 16CP of the waveguide connection flange 15 provided in order to suppress the manufacturing and assembling variation, similarly to the carrier 30. In addition to the positioning pins 35 that improve the positioning accuracy of the microstrip wiring board 20, the rectangular waveguide 10 and the casing 40, and the rectangular waveguide 10 and the connection destination waveguide 10S are provided between the casing 40 and the casing 40. Pins 15CP and 16CP are provided in order to suppress manufacturing and assembly variations.

  In general, the rectangular waveguide 10 and the housing 40 are connected by a screw 16, but by using the pin 16CP at the time of manufacture, the microstrip wiring board 20 can be screwed after being positioned in advance. Variations in manufacturing and assembly can be reduced, and deterioration of reflection characteristics of the waveguide microstrip line converter can be suppressed.

  In addition to the connection between the rectangular waveguide 10 and the housing 40, the waveguide microstrip line converter has a connection destination waveguide 10S. By using the pin 15CP provided on the waveguide connection flange 15 for the connection between the connection destination waveguide 10S and the rectangular waveguide 10, the positioning accuracy at the time of fixing with the screw 15 can be improved, and the reflection characteristics Can be prevented.

  With the above configuration, the waveguide microstrip line converter according to the second embodiment is connected not only to the positioning accuracy of the microstrip wiring board 20 but also between the waveguide 10 and the housing 40 and to the waveguide 10. It is possible to realize a structure that is robust against variations in manufacturing and assembly in consideration of the interface portion with the leading waveguide 10S.

Embodiment 3 FIG.
Waveguide microstrip line transducer according to the third embodiment, as shown in FIG. 11, the width of the strip conductors 22C are gradually changed in three stages, the first strip conductor 22C ₁ and the second strip conductor The point constituted by 22C ₂ and the third strip conductor 22C ₃ is different from the waveguide microstrip line converter of the first embodiment. Others are the same as those of the waveguide microstrip line converter of the first embodiment. Microstrip line 22MC on microstrip circuit board 20 is a rectangular waveguide 10, via the 22C ₃ from the first narrow width than the microstrip line 22MC from the third strip conductor 22C _1, probe conductor 22P Is the same as the waveguide microstrip line converter according to the first embodiment.

  In addition to the effect of the waveguide microstrip line converter of the first embodiment, the waveguide microstrip line converter of the third embodiment can obtain a smoother transmission characteristic and can have a wider band. It becomes. That is, by gradually changing the impedance stepwise, the microstrip wiring board 20 of the third embodiment can draw a plurality of circles near the center with respect to the loci of the low-frequency to high-frequency impedance on the Smith chart. . For this reason, it is possible to easily create a frequency resonance point, and the reflection characteristic can be broadened.

  Also in the third embodiment, the dielectric substrate 21 is placed on a conductive carrier 30 as a support body whose length and position in the rectangular waveguide 10 can be adjusted. The dielectric substrate 21 is fixed in a state where the position is adjusted on the carrier 30 and impedance matching is achieved. The waveguide microstrip line converter 100 mutually converts an electromagnetic wave propagating in the rectangular waveguide 10 and an electric signal transmitted on the microstrip line 22MC on the probe conductor 22P of the microstrip wiring board 20. .

  In the waveguide microstrip line converter according to the third embodiment, the strip conductor is changed in three stages. However, the strip conductor may be further multi-staged and may have a shape in which the line width changes smoothly. In addition to the effect of the waveguide microstrip line converter according to the first embodiment, a smoother transmission characteristic can be obtained, and a wider band can be realized. That is, by gradually changing the impedance stepwise, the microstrip wiring board 20 of the third embodiment draws more circles near the center with respect to the loci of the low-frequency to high-frequency impedance on the Smith chart. Can do. For this reason, it is possible to easily create a frequency resonance point, and the reflection characteristic can be broadened.

  Further, the configuration of the carrier 30 can be changed as appropriate. For example, the connection of the microstrip wiring board 20 to the carrier 30 is fixed by a conductive adhesive. However, by attaching a fixing clip to the carrier 30 and sandwiching the microstrip wiring board 20 with the fixing clip, the microstrip wiring board 20 can be attached and detached. It becomes easy. In connection with the fixing clip, it is necessary to make the contact resistance as small as possible, and it may be fixed by pressure bonding, and solder or conductive resin may be poured into the gap. When it is just enough to pour into the gap, it can be melted with a little heat or easily detached by a mechanical method.

  Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope of the invention, and are included in the invention described in the claims and the equivalents thereof.

10 rectangular waveguide, 10S connected waveguide, 11 waveguide body, 11S side, 12 short-circuited surface, 13 window, 14 opening, 15 waveguide flange, 15N screw, 15CP pin, 16 for housing connection Flange, 16N screw, 16CP pin, 20 microstrip wiring board, 21 dielectric board, 22 wiring, 22MC microstrip line, 22C strip conductor, 22C ₁ first strip conductor, 22C ₂ second strip conductor, 22C ₃ third strip Conductor, 22P probe conductor, 22G ground conductor, 30 carrier, 31 carrier body, 32 through hole, 33 screw, 34 positioning hole, 35, positioning pin, 40 housing, 41 housing body, 42 flange, 43 mounting hole, 100 Waveguide microstrip line converter.

Claims (6)

A waveguide having a short-circuited surface at one end, a window on a side surface orthogonal to the short-circuited surface, and an opening at the other end;
A microstrip wiring substrate comprising a dielectric substrate having one end inserted from the window of the waveguide and having a microstrip line on a main surface orthogonal to the short-circuited surface;
With
The microstrip line is connected to the probe conductor in the waveguide through a strip conductor that is narrower than the microstrip line,
The dielectric substrate is placed on a support whose length and position in the waveguide can be adjusted,
A waveguide microstrip line converter characterized in that on the probe conductor, an electromagnetic wave propagating in the waveguide and an electric signal transmitted on the microstrip line are mutually converted.   The said microstrip wiring board is fixed with respect to the wall part of a housing | casing, and was mounted on the support body which consists of a carrier which can adjust the attachment position with respect to the wall part of the said housing | casing. A waveguide microstrip line converter as described.   The carrier is fixed with an elongated hole and a screw that is inserted into the wall portion from the elongated hole, and by adjusting the position of the screw within the elongated hole, the position relative to the wall portion can be adjusted. The waveguide microstrip line converter according to claim 2.   The guide according to claim 3, wherein the support includes a screw and a positioning pin for adjusting a protrusion amount of the dielectric substrate into the waveguide and a distance from the waveguide short-circuit surface. Wave tube microstrip line converter. The microstrip wiring board is housed in a housing,
The housing includes a housing body that houses the microstrip wiring substrate, and a flange that is provided at a contact portion between the housing body and the waveguide,
2. The waveguide microstrip line converter according to claim 1, wherein a positioning pin is provided at a flange connecting portion between the waveguide and the housing body.   The strip conductor has a first strip conductor connected to the probe conductor, and a second strip conductor connected to the first strip conductor, from the probe conductor to the first strip conductor, 2. The waveguide microstrip line converter according to claim 1, wherein the width gradually decreases toward the second strip conductor.

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