JP3843946B2 - Waveguide converter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a waveguide converter that couples two metal plates to form a plurality of waveguide paths on a coupling surface and transmits a high-frequency signal, and more particularly to a high-frequency signal that propagates through a waveguide path. This relates to the reduction of mutual interference between the waveguide paths.
[0002]
[Prior art]
As a means for reducing mutual interference of high frequency signals due to leakage of signals between adjacent spaces provided with a high frequency transmission path, the space formed by the housing and the cover is separated by a partition plate, and the partition plate and the housing are separated. There is a conventional technique in which a conductive rubber material is provided between the bodies, and the cover is screwed to the housing and the partition plate so that the cover and the partition plate are brought into close contact by the repulsive force of the conductive rubber material (for example, patents) Reference 1).
[0003]
[Patent Document 1]
JP-A-8-186401 (page 2-4, FIG. 1)
[0004]
[Problems to be solved by the invention]
In the above prior art, the metal surface is only in contact between the cover and the partition plate due to the repulsive force of the conductive rubber material, and a slight gap is generated due to the processing accuracy of the metal surface. I can't solve that. In particular, when high-frequency signals such as microwaves or millimeter waves are transmitted, this gap becomes a low-impedance parallel plate waveguide, and the high-frequency signals in each space leak through each other and interfere with each other. Since isolation cannot be ensured, there is a concern that the propagation characteristics of high-frequency signals are deteriorated.
[0005]
In addition, the above-described prior art is such that a high frequency propagates through a transmission line on a dielectric substrate mounted in each space, and the shape of the space itself does not require strict accuracy. However, when the above prior art is applied to a waveguide converter that couples two metal plates to form a plurality of waveguide paths on the coupling surface and transmits a high-frequency signal, the space itself becomes a high-frequency signal. When it is required to have high precision because it functions as a waveguide that propagates, and when multiple waveguides must be densely placed due to dimensional constraints, the partition plate is a separate part and conductive rubber is used. Incorporating via material is not practical. It is realistic to provide a partition wall corresponding to the partition plate integrally on one of the two metal plates to form a waveguide path, but even in this case, depending on the processing accuracy at the joint of the two metal plates As described above, there is a concern that a gap is formed and high-frequency signals interfere with each other between adjacent waveguide paths, leading to deterioration of propagation characteristics.
[0006]
The present invention has been made to solve the above-mentioned problems, and has an object to reduce a mutual interference between adjacent waveguide paths and to obtain a waveguide converter having a good propagation characteristic. And
[0007]
[Means for Solving the Problems]
The waveguide converter according to the present invention has a plurality of waveguide paths formed on the coupling surface of the first metal plate and the second metal plate, and having a plurality of waveguide openings at different positions. In a waveguide converter that transmits high-frequency signals between devices such as high-frequency devices or antennas that transmit and receive high-frequency signals,
The first metal plate has a position facing one waveguide opening of the device.
A plurality of waveguide openings are provided, and the second metal plate is provided with a plurality of waveguide openings at a position facing the other waveguide opening of the device, and the first metal A first groove serving as a waveguide path connecting between the waveguide openings of the plate and the second metal plate is provided, and the first groove adjacent to the first groove is adjacent to the first groove. The depth of the partition wall between the grooves and the first metal plate is less than ¼ of the free space propagation wavelength of the high-frequency signal propagating through the waveguide, A second groove is provided at least 10 times the gap at the joint surface with the second metal plate .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
1 is a perspective view showing a waveguide converter according to Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view taken along line AA ′ of FIG. 1, and FIG. 3 is a cross-sectional view taken along line BB of FIG. 4 is a cross-sectional view, and FIG. 4 is a plan view showing the second metal plate 3 according to the first embodiment of the present invention. In the figure, the first metal plate 1 is provided with a plurality of waveguide openings 2, and the second metal plate 3 has a waveguide opening 2 at a position different from the waveguide openings 2. The same number of waveguide openings 4 are provided. A first groove 5 that connects both the waveguide openings 2 and 4 is provided in the second metal plate 3, and the first metal plate 1 and the second metal plate 3 are connected by screws 6. A waveguide converter having a waveguide 7 through which a high-frequency signal propagates is formed. Equipment such as a high-frequency device or an antenna (not shown) that transmits and receives a high-frequency signal (not shown) having waveguide openings at positions facing the waveguide openings 2 and 4 on both surfaces of the waveguide converter. Are connected, and high-frequency signals can be transmitted between devices having different waveguide opening positions. When connecting the first metal plate 1 and the second metal plate 3 with the screws 6, a gap 8 is formed on the joint surface due to processing accuracy. The partition wall 9 between the adjacent first grooves 5 is provided with a second groove 10 whose depth is an odd multiple of approximately 1/4 of the free space propagation wavelength λ of the high-frequency signal.
[0009]
In the waveguide converter configured as described above, when a high-frequency signal propagates through the waveguide, the high-frequency signal passes through the gap 8 from one of the adjacent waveguides 7 to the other. Leakage occurs. The leakage of the high-frequency signal occurs when the gap 8 becomes a low impedance parallel plate waveguide and currents in opposite phases flow on the upper and lower surfaces of the gap 8. Here, the second groove 10 is provided only on one of the upper and lower surfaces of the gap 8 by providing the second groove 10 whose depth is an odd multiple of approximately 1/4 of the free space propagation wavelength λ of the high-frequency signal. The current flowing on the selected side flows through a distance twice as long as the depth of the second groove 10, that is, an odd number times longer than about half of the free space propagation wavelength λ of the high-frequency signal, and the phase is inverted. Therefore, up to the second groove 10, the current flowing through the upper and lower surfaces of the gap 8 has an opposite phase, but after passing through the second groove 10, only one of the phases is reversed, and the upper and lower surfaces of the gap 8 are The flowing currents have the same phase, the high-frequency signal does not leak before the gap 8, and mutual interference between the adjacent waveguides 7 can be suppressed.
[0010]
Embodiment 2. FIG.
The second embodiment has the same configuration as that of FIGS. 1 to 4 showing the first embodiment, and the depth of the second groove 10 is less than ¼ of the free space propagation wavelength λ of the high-frequency signal. , At least 10 times the distance of the gap 8.
[0011]
The characteristic impedance of the parallel plate waveguide formed between the upper and lower surfaces of the gap 8 is different between a portion where the second groove 10 is provided and a portion where the second groove 10 is not provided. Since the characteristic impedance is proportional to the distance between the upper and lower surfaces of the parallel plate waveguide, if the depth of the second groove 10 is at least 10 times the distance of the gap 8, the second groove 10 is approximately equal to this magnification. There is a mismatch in characteristic impedance between the portion where there is and the portion where the second groove 10 is not provided. Due to this characteristic impedance mismatch, the high-frequency signal leaking into the gap 8 at the boundary between the portion with the second groove 10 and the portion without the second groove 10 causes a mismatch in the characteristic impedance. The corresponding amount is reflected and the high-frequency signal passing therethrough can be reduced. For example, if the depth of the second groove 10 is about 40 times the distance of the gap 8, the high-frequency signal that passes through the boundary portion between the portion where the second groove 10 is present and the portion where the second groove 10 is absent. , About -10 dB, that is, about 1/10. Since this boundary portion is formed at two locations on both sides of the second groove 10, the high-frequency signal leaking from one of the adjacent waveguides 7 to the other is reduced to about -20 dB, that is, about 1/100. it can. As described above, even when the depth of the second groove 10 cannot be deeply formed to about 1/4 of the free space propagation wavelength λ of the high-frequency signal shown in the first embodiment due to processing restrictions, the gap 8 The high-frequency signal leaking from one of the adjacent waveguide paths 7 to the other can be greatly reduced by setting the distance to at least 10 times or more, preferably about 40 times or more of the distance between the adjacent waveguide paths 7. Mutual interference can be suppressed.
[0012]
Embodiment 3 FIG.
5 is a perspective view showing a waveguide converter according to Embodiment 3 of the present invention, and FIG. 6 is a cross-sectional view taken along the line CC ′ of FIG. In the figure, the second groove 10 is provided in the first metal plate 1. In the first or second embodiment, the second groove 10 is provided in the partition wall 9 of the second metal plate 3, but even if the second groove 10 is provided in the first metal plate 1, In addition to the effect that the mutual interference between the adjacent waveguides 7 can be suppressed, the width of the partition wall 9 is not sufficient, and the second groove 10 is provided in the partition wall 9. The problem that the thickness between the first and second grooves 10 is thin and the processing is difficult or the strength is insufficient can be solved.
[0013]
Embodiment 4 FIG.
This Embodiment 4 has a dimension obtained by offsetting the length L of the second groove 10 from an integer multiple of approximately ½ of the free space propagation wavelength λ of the high-frequency signal in any of Embodiments 1 to 3. It is what.
[0014]
When the length L of the second groove 10 is an integral multiple of approximately half the free space propagation wavelength λ of the high-frequency signal, the second groove 10 leaks into the second groove 10 from one waveguide 7. Since the high frequency signal resonates in the longitudinal direction in the space of the second groove 10 and the high frequency signal is amplified and flows back through the gap 8, the high frequency signal that has flowed back in the waveguide path 7. However, in the above-mentioned waveguide converter, the length L of the second groove 10 is set to approximately half the free space propagation wavelength λ of the high-frequency signal. By making the dimensions offset from an integral multiple, resonance of the high-frequency signal in the longitudinal direction in the space of the second groove 10 does not occur, and there is no possibility of causing deterioration of propagation characteristics.
[0015]
Embodiment 5 FIG.
7 is a perspective view showing a waveguide converter according to Embodiment 5 of the present invention, FIG. 8 is a sectional view taken along the line DD ′ of FIG. 7, and FIG. 9 is an embodiment of the present invention. 5 is a plan view showing a second metal plate 3 in FIG. The second embodiment is the same as the first or second embodiment except for the second groove 10. In the present embodiment, the length L of the second groove 10 is less than ½ of the free space propagation wavelength λ of the high-frequency signal, and the second groove 10 is arranged in two rows in a staggered manner.
[0016]
In the above-described waveguide converter, the length L of the second groove 10 is set to be less than ½ of the free space propagation wavelength λ of the high-frequency signal, so that the second groove 10 is the same as in the fourth embodiment. The resonance of the high frequency signal in the longitudinal direction in the space of 10 does not occur and there is no possibility of causing the deterioration of the propagation characteristics, and the second groove 10 is arranged in two rows in a staggered manner, so that the second in the first row The high-frequency signal that has passed through the gap between the grooves 10 also stops leaking in the second groove 10 in the second row, and the mutual interference between the adjacent waveguides 7 can be suppressed.
[0017]
Embodiment 6 FIG.
10 is a perspective view showing a waveguide converter according to Embodiment 6 of the present invention, and FIG. 11 is a cross-sectional view taken along line EE ′ of FIG. In the drawing, one row on one side of the second grooves 10 arranged in a staggered manner in two rows is provided on the first metal plate 1. In the fifth embodiment, the second grooves 10 arranged in a staggered manner in two rows are provided in the partition walls 9 of the second metal plate 3, but the second grooves 10 arranged in a staggered manner in two rows are included in the second grooves 10. Even if at least one of the rows is provided on the first metal plate 1, similarly, there is no risk of causing deterioration of propagation characteristics due to resonance, and it is possible to suppress mutual interference between adjacent waveguide paths 7. In addition, when the partition wall 9 is not sufficiently wide and the partition wall 9 is provided with the second groove 10, the thickness between the first groove 5 and the second groove 10 and in two rows The problem that the thickness between the second grooves 10 arranged in a staggered manner is thin and the processing is difficult or the strength is insufficient can be solved. In particular, when only one row of the second grooves 10 arranged in a staggered manner in two rows is provided on the first metal plate 1, the partition walls between the second grooves 10 are eliminated, and the processing and strength are increased. More advantageous.
[0018]
【The invention's effect】
As described above, according to the present invention, a groove is provided in the joint surface between the first metal plate and the partition wall formed between the waveguides, and the depth of the second groove is set according to the freedom of the high frequency signal. Even when it cannot be formed as deep as about ¼ of the spatial propagation wavelength λ, the mutual interference between the adjacent waveguides can be reduced by setting it to at least 10 times the distance of the gap 8 , and good propagation characteristics can be obtained. Can be obtained.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a configuration of a waveguide converter according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of the waveguide converter according to the first embodiment of the present invention, taken along the line AA ′ in FIG.
3 is a cross-sectional view of the waveguide converter according to the first embodiment of the present invention, taken along the line BB ′ in FIG.
FIG. 4 is a plan view showing a first metal plate of the waveguide converter according to the first embodiment of the present invention.
FIG. 5 is a perspective view showing a configuration of a waveguide converter according to a third embodiment of the present invention.
6 is a cross-sectional view taken along the line CC ′ in FIG. 5 of a waveguide converter according to a third embodiment of the present invention.
FIG. 7 is a perspective view showing a configuration of a waveguide converter according to a fifth embodiment of the present invention.
8 is a cross-sectional view taken along the line DD ′ in FIG. 7 of a waveguide converter according to a fifth embodiment of the present invention.
FIG. 9 is a plan view showing a first metal plate of a waveguide converter according to a fifth embodiment of the present invention.
FIG. 10 is a perspective view showing a configuration of a waveguide converter according to a sixth embodiment of the present invention.
FIG. 11 is a cross-sectional view taken along line EE ′ in FIG. 10 of a waveguide converter according to a sixth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 1st metal plate, 2 Waveguide opening part, 3rd metal plate, 4 Waveguide opening part, 1st groove | channel, 6 Screw, 7 Waveguide path, 8 Gap, 9 Bulkhead, 10 Second groove

Claims (5)

A high-frequency device or antenna that forms a plurality of waveguide paths on the coupling surface between the first metal plate and the second metal plate, has a plurality of waveguide openings at different positions, and transmits and receives a high-frequency signal In a waveguide converter that transmits high-frequency signals between devices such as
The first metal plate is provided with a plurality of waveguide openings at positions facing one waveguide opening of the device,
The second metal plate is provided with a plurality of waveguide openings at positions facing the other waveguide opening of the device, and each of the first metal plate and the second metal plate is provided. A first groove serving as a waveguide path that connects between the waveguide openings is provided, and the first groove of the partition between the adjacent first grooves is provided at a location where the first groove is adjacent. A junction surface between the first metal plate and the second metal plate, the depth of which is less than ¼ of the free space propagation wavelength of the high-frequency signal propagating through the waveguide, on the junction surface with the metal plate A waveguide converter characterized in that a second groove at least 10 times the gap is provided. 2. The waveguide converter according to claim 1, wherein the second groove is provided on a joint surface of the first metal plate facing a partition wall between the adjacent first grooves. Wherein the length of the second groove, claim 1 or claims, characterized in that the dimensions are offset from integer multiples of the outline half the free-space propagation wavelength of the high frequency signal propagating through the waveguide path Item 3. The waveguide converter according to Item 2 . Wherein the length of the second groove, the waveguide path is less than half of the free space propagation wavelength for high-frequency signal propagated, guide according to claim 1, characterized in that a staggered arrangement of the two rows Wave tube converter. At least one of the second grooves arranged in a staggered arrangement of the two rows is provided on a joint surface of the first metal plate facing a partition wall between the adjacent first grooves. The waveguide converter according to claim 4 .

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