JP2005020077A - 90 degree bent waveguide, waveguide filter element, and high frequency circuit unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized high performance 90° bent waveguide, a waveguide filter element, and a high frequency circuit unit. <P>SOLUTION: The 90° bent waveguide is provided which includes a metallic member 101 formed almost a rectangular solid on the front side of which a groove equivalent to a guide diameter of a first waveguide is formed and on the rear side of which a second waveguide having an opening and orthogonal to the groove; metallic members 102a, 102b fitted to the groove in a way that the end face has a 45-degree tapered face and the 45° tapered face is opposed to the opening of the second waveguide at an orthogonal part between the groove and the second waveguide, and a metallic plate 103 for covering the groove and forming the first waveguide. Further, the high frequency circuit is provided, which comprises an antenna, a high frequency circuit and the waveguide filter element wherein the 90° bent waveguide is formed at an end of the metallic member 101 formed almost the rectangular solid for forming a filter part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high-frequency circuit unit including an antenna and a filter element, and more particularly to a miniaturized high-frequency circuit unit suitable for a millimeter wave frequency region and a quasi-millimeter wave frequency region.
[0002]
[Prior art]
Conventionally, this type of small high-frequency circuit unit has a structure disclosed in Patent Document 1, and a high-frequency signal processing circuit is formed on a printed wiring board on which a patch antenna is formed. Was an integrated structure. Patent Document 2 shows the structure of a semiconductor module incorporating an antenna. In the above prior art, an amplifier circuit, a frequency conversion circuit, and an oscillator circuit are shown as the high-frequency signal processing circuit.
[0003]
On the other hand, FIG. 11 shows a wireless device circuit configuration in the millimeter wave frequency region using conventional individual components. The configuration is such that the modulation signal from the intermediate frequency circuit (not shown) is frequency-converted by a millimeter wave signal generated by a local oscillator, amplified by an amplifier, and then a frequency band unnecessary for communication is removed by a filter element. It radiates from the antenna into the air. Here, a waveguide, a coaxial connector, or the like is used for connection between independent individual circuit components.
[0004]
In FIG. 11, an antenna 601 having a waveguide output and a waveguide filter element 602 are connected by flanges 611a and 611b at the waveguide ends, and a waveguide-coaxial connector conversion is performed at the other end of the filter element. The device 603 is connected by a flange. After being converted to the coaxial connector, it is connected to the circuit module 604 incorporating the amplifier circuit and the frequency conversion circuit, and the local oscillator 605 by coaxial cables 612a and 612b. The filter element used here is a waveguide type filter because it is desirable to cut off the outside of the passband as steeply as possible and to have a small insertion loss in consideration of effective use of radio frequencies. An element is used.
[0005]
[Patent Document 1]
JP-A-3-9602
[Patent Document 2]
JP-A-10-79623
[0006]
[Problems to be solved by the invention]
By the way, the conventional small high-frequency circuit unit does not include a filter element that is indispensable as a wireless device. If a filter element that can be included is used, it is composed of a planar circuit using a stripline or a microstripline. Only small filters are applicable. However, such a small flat filter has a poor cutoff characteristic outside the passband and a large insertion loss, which causes the circuit characteristics to deteriorate. In addition, in the conventional wireless device configuration, waveguides, coaxial connectors, etc. are used for connection between individual circuit components, so there is a limit to miniaturization, and it is possible to manufacture small wireless devices with high market needs. This was impossible, and the reflection loss at each connection point increased, causing deterioration of circuit characteristics.
[0007]
The present invention has been made in view of the above-mentioned problems of conventional high-frequency circuit units, and an object of the present invention is a novel and improved 90-degree bend type waveguide having a reduced size and excellent circuit characteristics. It is to provide a tube, a waveguide type filter element, and a high frequency circuit unit.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, according to the present invention, in a 90-degree bend type waveguide that bends the propagation direction of radio waves by 90 degrees; the surface corresponds to the diameter (cross-sectional size) of the first waveguide. A first metal member having a substantially rectangular parallelepiped shape in which a groove is formed and a second waveguide having the same tube diameter as the first waveguide is provided with an opening on the back surface perpendicular to the groove; Is a 45-degree tapered surface, and the 45-degree tapered surface is fitted into the groove so that the 45-degree tapered surface faces the opening of the second waveguide at an orthogonal portion between the groove and the second waveguide. There is provided a 90-degree bend waveguide characterized in that it includes two metal members and a third metal member that covers the groove to complete the first waveguide.
[0009]
Here, the second metal member fitted in the groove has a length of about 0.202 L connected to the side surface of the second waveguide at the end when the short side length of the waveguide cross section is L. It is preferable that a 45-degree tapered surface is formed, leaving the vertical surface of the film, and reflection characteristics can be improved. The length of the vertical surface is preferably 0.096L to 0.308L in consideration of the processing accuracy of the metal member.
[0010]
The 90-degree bend waveguide of the present invention reduces the reflection at the bend and reduces the transmission characteristics compared to the conventional structure in which the λ / 4 short waveguide is formed on the 90-degree bend of the rectangular waveguide. Can be good. In addition, it can be remarkably reduced in size as compared with a 90-degree bend structure obtained by bending a conventional rectangular waveguide. Furthermore, since a metal member having a shape that can be easily processed is fitted, a small 90-degree bend type waveguide that is easy to manufacture and suitable for mass production and has good reflection characteristics can be obtained.
[0011]
In addition, a groove serving as a waveguide and a filter portion having a plurality of booths are formed on the surface of a substantially rectangular parallelepiped metal member, and the 90-degree bend waveguide is formed at one or both ends of the groove. By doing so, it is possible to provide a 90-degree bend type waveguide-integrated waveguide filter element whose outer shape is reduced in size and thickness. In addition, the filter part is processed from the surface of a substantially rectangular parallelepiped metal member, and is completed by covering with a plate-like metal member, so that it can be processed with high accuracy, no adjustment in the subsequent process is required, and the element is inexpensive. Can be manufactured.
[0012]
Furthermore, by using the above-described 90-degree bend waveguide integrated waveguide filter element, an antenna formed from a planar circuit and a high-frequency circuit board are integrally formed on the back surface of the waveguide filter element, thereby reducing the size. Therefore, it is possible to provide a high-frequency circuit unit that has good performance, is inexpensive and suitable for mass production.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The 90-degree bend waveguide, waveguide filter element, and high-frequency circuit unit according to the present embodiment will be described in detail below with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.
[0014]
(First embodiment)
FIG. 1A shows a 90-degree bend waveguide according to this embodiment, and is a schematic explanatory view showing, for example, a 90-degree bend (E bend) portion of an electric field surface of a rectangular waveguide. A groove corresponding to the tube diameter (cross-sectional size) of the first waveguide is formed on the surface of a substantially rectangular parallelepiped metal member 101 that is the first metal member, and a part of the groove intersects perpendicularly with the groove. The rectangular parallelepiped metal member 101 has a second waveguide having an opening on the back surface and having the same tube diameter as the first waveguide. Metal plates 102a and 102b, which are second metal members having a taper surface (slope) of 45 degrees on one side, are fitted into intersecting portions of the orthogonal waveguides, and then a metal plate which is a third metal member covering the groove The E-bend portion of the rectangular waveguide is configured by screwing 103 to the groove forming surface of the substantially rectangular parallelepiped metal member 101.
[0015]
FIG. 1B is an explanatory diagram showing a cross-sectional structure of the waveguide E bend portion. In the present embodiment, the following processing is performed on the metal members 102a and 102b having a 45-degree tapered surface (slope) to improve the reflection characteristics at the waveguide E bend. First, assuming that the length of the short side of the rectangular waveguide is L, the metal member 102a, 102b having a 45 degree taper surface (slope) leaves a vertical surface of about 0.202 L and a 45 degree taper. A surface (slope) is formed. This length is preferably 0.202 L ± 0.106 L (0.096 L to 0.308 L). Thereafter, the vertical surface is fitted into a groove formed in the substantially rectangular parallelepiped metal member 101 so as to form the same plane as the long-diameter side of the rectangular waveguide. Here, the arrows described in FIGS. 1A and 1B indicate the propagation directions of radio waves.
[0016]
In the metal member 102 having such a structure, for example, when the rectangular waveguide is WR15, the short side diameter of the waveguide is 1.88 mm. Therefore, the vertical surface to be formed is 0.38 ± 0.2 mm. Therefore, it can be processed sufficiently with the existing processing accuracy. Further, the thickness of the metal member 102 is processed to be equal to the short side length of the waveguide, and the width is processed to be equal to the long side length of the waveguide.
[0017]
FIG. 12 is an explanatory view showing the structure of a conventional waveguide E bend portion. A groove having a shape corresponding to the tube diameter of the rectangular waveguide is formed on the surface of the substantially rectangular parallelepiped metal member 201, and the intersection of the waveguides is shown. The metal member 202 is fitted into the portion, and a waveguide (short waveguide) having a length D of λ / 4 (λ: propagation wavelength) in FIG. 12 is formed in the waveguide E bend portion. And the E-bend portion of the rectangular waveguide is formed.
[0018]
The graph of FIG. 2 compares the simulation results of the transmission characteristics of the rectangular waveguide E bend of the present embodiment and the conventional rectangular waveguide E bend shown in FIG. Obviously, the rectangular waveguide E bend structure of the present embodiment shows less bend reflection (−20 dB or less) over a wide band (50 to 75 GHz).
[0019]
In addition, this embodiment can obtain a significantly smaller rectangular waveguide E bend compared to an E bend obtained by bending a conventional rectangular waveguide with a finite curvature (for example, R = 0.5 inch). As described above, when the rectangular waveguide E bend structure of the present embodiment is used, a rectangular waveguide E bend with very little bend reflection and a small external shape can be obtained by a simple method. .
[0020]
(Second Embodiment)
FIG. 3 is an explanatory diagram showing the structure of the waveguide filter element according to the second embodiment. For example, the waveguide E bend shown in the first embodiment is provided at both ends of the waveguide filter section. Has a part.
[0021]
A groove having a shape corresponding to the tube diameter of the rectangular waveguide is formed on the surface of the substantially rectangular parallelepiped metal member 301 as the first metal member, and a thin partition having a slit at the center is formed in the groove. A booth 304 is formed to filter the frequency of the. Similarly to the first embodiment, the grooves at both ends of the filter section have waveguides having the same tube diameter that intersect perpendicularly to the grooves and have openings formed on the back surface of the substantially rectangular parallelepiped metal member 301. ing. Also, metal members 302a and 302b, which are second metal members having a vertical surface similar to that of the first embodiment and a taper surface (slope) of 45 degrees, are fitted into the orthogonal portion of the groove and the waveguide, and thereafter A waveguide type filter element is formed by, for example, screwing a metal plate 303 as a third metal member covering the surface of the substantially rectangular parallelepiped metal member 301 on which the opening filter portion is formed.
[0022]
Here, the filter unit will be further described. FIG. 4 shows an example of the shape of the three-stage filter. The pitches P1 and P2 of the partitions (in-tube protrusions) and the spaces S1 and S2 between the protrusions are parameters that influence the filter characteristics. An electromagnetic simulator is used to calculate the numerical value of each parameter, and the value is determined by adjusting the value of each parameter while observing the resulting filter characteristics.
[0023]
In the manufacture of conventional waveguide filters, high processing accuracy is required for processing to the design values of each parameter, resulting in frequency deviation from the design values and transmission loss variations within the filter band. Fine adjustment is required later for the purpose of correcting the filter characteristics. However, in the filter of the present embodiment, a groove conforming to the design shape can be formed with high precision from the surface of a substantially rectangular parallelepiped metal member by milling, and finally the filter portion is covered with a metal plate to complete the filter element. , The second fine adjustment step can be eliminated.
[0024]
The operation of the waveguide filter element of the present embodiment is described in the first embodiment by inputting a radio wave from one opening formed through the waveguide on the back surface of the substantially rectangular parallelepiped metal member 301. Through the E-bend portion, the radio wave is bent 90 degrees in the direction of the filter forming surface of the substantially rectangular parallelepiped metal member 301, passes through the booth 304 showing a predetermined filter characteristic, and then passes through the E-bend portion again to the other opening on the back surface Guides radio waves.
[0025]
As described above, according to the second embodiment, by using the rectangular waveguide E bend structure described in detail in the first embodiment, a very small and thin waveguide filter element can be obtained. It became possible to form. Furthermore, since all the thin partition plates having slits for forming the filter can be processed with high precision from the surface, the steps such as fine adjustment after manufacturing are not required as in the case of the conventional waveguide type filter element, leading to low cost. It became possible to manufacture a wave tube type filter element. In addition, since all processing can be performed from the surface of a substantially rectangular parallelepiped metal member, it can be manufactured using an injection molding method or the like without being troubled by cutting, and the structure is suitable for mass production of high-precision waveguide filters.
[0026]
(Third embodiment)
4 to 6 are explanatory views showing the structure of a high frequency unit in which an antenna is integrally formed with a waveguide type filter element according to the second embodiment as a third embodiment. FIG. 4A is a schematic cross-sectional view showing the high-frequency unit according to the present embodiment. As in the second embodiment, a substantially rectangular parallelepiped metal member 401, which is a first metal member, and a waveguide filter section. Metal members 402a and 402b which are second metal members fitted into the waveguide grooves at both ends of the metal plate, a metal plate 403 which is a third metal member covering the surface of the groove, and two wiring boards on which antennas are formed 405 and 406. The present embodiment further includes a wiring board pressing portion 404 that is a fourth metal member that sandwiches the wiring boards 405 and 406 with the substantially rectangular parallelepiped metal member 401.
[0027]
In addition, the wiring board holding portion 404 is a waveguide / planar circuit formed on the wiring boards 405 and 406 that receives radio waves that are filtered and output from the opening on the back surface of the substantially rectangular parallelepiped metal member 401 through the waveguide. In order to improve the reflection characteristics of the converter, a through-hole is formed in a waveguide having a length of λ / 4 (λ: propagation wavelength) (hereinafter referred to as a short waveguide) and in an area that does not interfere with radio wave radiation from the antenna. A formed wiring board pressing portion 404 is included.
[0028]
Next, the operation of the high frequency unit integrated with the antenna and the waveguide type filter element will be described while explaining details of each component. FIG. 4B is a perspective view of a substantially rectangular parallelepiped metal member 401. As in the second embodiment, a slit is formed at the center of the waveguide in order to form a waveguide groove forming a waveguide filter from the surface of the substantially rectangular parallelepiped metal member 401 and a booth 410 exhibiting predetermined filter characteristics. A partition with is formed. E-bend portions are formed at both ends of the substantially rectangular parallelepiped metal member 401, one of which reflects radio waves outward from the surface of the substantially rectangular parallelepiped metal member 401 to the waveguide penetrating the back of the substantially rectangular parallelepiped metal member 401. It has a structure.
[0029]
Since the E-bend structure used here is the same as that of the first embodiment, description thereof is omitted. The metal plate 403 covering the filter portion is formed with an opening 411 for introducing a radio wave into the waveguide from the outside. With the above structure, the substantially rectangular parallelepiped metal member 401 operates as follows. The radio wave incident from the opening 411 is transmitted to the filter unit by the E bend formed by the metal member 402b, filtered to a predetermined frequency characteristic, and then substantially rectangular parallelepiped metal by the E bend formed by the metal member 402a. It is output to the opening 412 on the back surface of the member 401.
[0030]
Next, the structure of the wiring boards 405 and 406 forming the antenna and the waveguide / planar circuit converter will be described with reference to FIGS. A metal conductor 413 is formed on the entire surface of one side of the wiring board 405, and has a conductor opening 414 at a location corresponding to the opening 412 of the substantially rectangular parallelepiped metal member 401. On the other surface, planar circuit wiring 416 is formed from the back surface portion of the conductor opening 414 and connected to a patch antenna 415 having a substantially rectangular conductor. The dielectric base material 417 of the wiring board 405 is exposed at portions other than the patch antenna 415.
[0031]
On the other hand, the wiring board 406 has an opening 420 in a region that does not inhibit radio wave radiation from the antenna centering on the patch antenna 415, and the dielectric substrate 421 is exposed on the surface facing the wiring board 405. A metal conductor 419 is formed on the entire back surface of the surface on which the body substrate 421 is exposed, and a conductor opening 418 is formed at a location corresponding to the opening 412.
[0032]
Next, the operation of the wiring boards 405 and 406 will be described. The radio wave emitted from the opening 412 of the waveguide is transmitted to the planar circuit wiring 416 that is sandwiched between the two conductor openings 414 and 418 and protrudes into the conductor openings 414 and 418. Thereafter, the signal is transmitted to the patch antenna 415 through the strip line formed by the metal conductors 413 and 419 and the planar circuit wiring 416 and the microstrip line in the opening 420 and radiated to the space.
[0033]
Next, the wiring board pressing portion 404 that is a structural member will be described with reference to FIG. The wiring board holding section 404 has an opening 423 in a region that does not inhibit radio wave radiation from the antenna centered on the patch antenna 415, sandwiches the wiring boards 405 and 406 together with the substantially rectangular parallelepiped metal member 401, screws, etc. The wiring boards 405 and 406 are brought into close contact with each other. In addition, a short waveguide 422 is formed at a location corresponding to the opening 412 to improve the reflection characteristics of the waveguide / planar circuit converter that transmits the radio wave from the waveguide opening 412 to the planar circuit wiring 416. ing.
[0034]
As described above, according to the third embodiment, the high-frequency unit can be significantly reduced in size by integrating the antenna with the small waveguide filter element described in the second embodiment. Thinning can be achieved. In addition, circuit loss can be reduced by using a waveguide filter. Furthermore, the cost of the high-frequency unit can be reduced because the manufacturing method is simple and the adjustment process is not necessary. Therefore, it is possible to obtain the effects of future miniaturization of millimeter-wave and quasi-millimeter-wave radios, improvement of circuit characteristics, and price reduction.
[0035]
(Fourth embodiment)
FIGS. 7 to 10 are explanatory views showing the high-frequency circuit unit of the fourth embodiment in which the waveguide filter element, the antenna, and the high-frequency circuit described in the second embodiment are integrally formed. is there. First, FIG. 7A is a schematic cross-sectional view of the high-frequency unit according to the fourth embodiment.
[0036]
As in the second embodiment, a substantially rectangular parallelepiped metal member 501 that is a first metal member having a groove formed therein, metal members 502a and 502b that are second metal members fitted in the groove, and a groove surface It is composed of a metal plate 503 that is a third metal member to be covered, two wiring boards 505 and 506 on which an antenna is formed, and a high-frequency circuit board 507. In the present embodiment, furthermore, the wiring boards 505 and 506 are sandwiched between the substantially rectangular parallelepiped metal members 501, and the waveguide / planar circuit conversion unit and the planar circuit / waveguide conversion formed on the wiring boards 505 and 506 are used. A wiring board pressing part 504, which is a fourth metal member in which a short waveguide is formed, and a high frequency circuit housing part cover 508 attached to the wiring board pressing part 504 and covering the high frequency circuit board 507. Yes.
[0037]
Next, the operation of the high-frequency unit according to the present embodiment will be described while explaining details of each component in FIG. FIG. 7B is a perspective view of a substantially rectangular parallelepiped metal member 501. In order to form a waveguide groove and a booth 510 having predetermined filter characteristics on the surface of a substantially rectangular parallelepiped metal member, a partition thin plate having a slit at the center of the waveguide is formed.
[0038]
E-bend portions are formed at both ends of the substantially rectangular parallelepiped metal member 501 so that radio waves are incident from one of the waveguides penetrating the substantially rectangular parallelepiped metal member 501 and radiated from the other. Since the structure of the waveguide E bend used here is the same as that of the first embodiment, the description thereof is omitted. A metal plate 503 that is a lid covering the filter portion is fixed to the substantially rectangular parallelepiped metal member 501 with a screw or the like. In addition, on the back surface of the substantially rectangular parallelepiped metal member 501, a storage portion 514 that stores a high-frequency circuit to be described later, and a recess 513 corresponding to a short waveguide of a circular waveguide antenna are formed. Further, a hole for attaching a connector 515 for introducing a signal and a power source from the outside is formed in the storage portion 514 of the high frequency circuit.
[0039]
With the above structure, the substantially rectangular parallelepiped metal member 501 operates as follows. The radio wave incident from the opening 511 is transmitted to the filter unit by the E bend formed by the metal member 502b, filtered to a predetermined frequency characteristic, and then substantially rectangular parallelepiped metal by the E bend formed by the metal member 502a. This is output to the other opening 512 of the member 501.
[0040]
Next, the structure of the wiring boards 505 and 506 forming the antenna and the waveguide / planar circuit converter will be described with reference to FIGS. A metal conductor 516 is formed on one surface of the wiring board 505 and has conductor openings 517 and 518 at locations corresponding to the openings 511 and 512 of the waveguide filter portion. Further, a conductor opening 519 is formed corresponding to the circular waveguide antenna forming portion, and an opening 520 is formed corresponding to the housing portion 514 of the high frequency circuit. On the other hand, planar circuit wirings 521 and 522 are formed on the opposite surface of the wiring board 505 from the back surface portions of the conductor openings 517 and 518, and the portions other than the planar circuit wirings 521 and 522 are the dielectric base material 523. Is exposed.
[0041]
On the other hand, the wiring board 506 has an opening 525 corresponding to the housing portion 514 of the high-frequency circuit, and the dielectric substrate 524 is exposed on the surface facing the wiring board 505, and the back surface of the surface of the dielectric substrate 524 A metal conductor 526 is formed on the entire surface, and conductor openings 527 and 528 are formed at positions corresponding to the openings 511 and 512 of the substantially rectangular parallelepiped metal member 501, and conductor openings are formed at positions corresponding to the circular waveguide antenna forming section. 529 is formed.
[0042]
Next, the operation of the wiring boards 505 and 506 will be described. A high-frequency signal output from a high-frequency circuit board 507, which will be described later, is transmitted to the planar circuit wiring 521 by a fine metal wire by, for example, a wire bonding method. After that, through a strip line formed by the metal conductors 516 and 526 of the wiring board and the planar circuit wiring 521, a planar circuit / plane comprising the planar circuit wiring 521 which is sandwiched between the two conductor openings 517 and 527 and protrudes into the conductor opening. It is transmitted to the opening 511 of the waveguide of the substantially rectangular parallelepiped metal member 501 by the waveguide converter.
[0043]
A high-frequency signal transmitted through the substantially rectangular parallelepiped metal member 501 to the waveguide opening 512 is sandwiched between the two conductor openings 518 and 528, and is formed of a planar circuit wiring 522 protruding into the conductor opening. Is transmitted to the planar circuit wiring 522 by the planar circuit converter, and is transmitted to the circular waveguide antenna at the other end of the planar circuit wiring 522 through the strip line formed by the metal conductors 516 and 526 of the wiring board and the planar circuit wiring 521. To be emitted.
[0044]
Next, the wiring board holding part 504 and the high frequency circuit storage part cover 508 which are structural members will be described. The wiring board holder 504 is formed with short waveguides 530 and 531 at locations corresponding to the planar circuit / waveguide converter and the waveguide / planar circuit converter described above. In addition, the reflection characteristics of the waveguide / planar circuit converter waveguide are improved. In addition, a cylindrical through hole 533 corresponding to the radiation waveguide of the circular waveguide antenna and a through hole 532 corresponding to a cavity for housing the high-frequency circuit board 507 are provided.
[0045]
A cylindrical through hole 533 corresponding to the radiation waveguide is opposed to a recess 513 corresponding to a short waveguide of a circular waveguide antenna formed in the substantially rectangular parallelepiped metal member 501, and the wiring boards 505 and 506. The conductor openings 519 and 529 formed in the metal conductors 516 and 526 have the same diameter, and the planar circuit wiring 522 protrudes into the circular waveguide sandwiched between the conductor openings 519 and 529 having the same center. A circular waveguide antenna is configured.
[0046]
For a circular waveguide antenna, reference S.A. Nishi, K .; Hamaguchi, T .; Matui, and H.M. Ogawa, “Development of Millimeter-wave video transmission system II, Antenna Development 10”, “Tenical Dimension of the Thr. The details are clearly described here, but the explanation is omitted here.
[0047]
In addition, a high frequency circuit storage unit cover 508 that covers the through-hole 532 corresponding to the cavity for storing the high frequency circuit board 507 is prepared. A high-frequency circuit storage unit lid 508 is fixed to protect and shield the internal high-frequency circuit board 507.
[0048]
Finally, the high-frequency circuit board 507 accommodated will be described. As shown in FIG. 9 (f), the high-frequency circuit board 507 is made of a metal plate on which various active elements 534a and 534b and passive components 535 are mounted, and the elements are connected in advance by thin metal wires by a wire bonding method or the like. As a semi-finished product, various characteristics can be evaluated. The high-frequency circuit board 507 is accommodated in the accommodating portion 514, connected to connectors 515 for introducing signals and power, and wired with the planar circuit wiring 521 to complete.
[0049]
Here, a method of housing the high-frequency circuit board 507 will be described in detail with reference to FIG. The high-frequency circuit board 507 is inserted into the storage portion 514 formed in the substantially rectangular parallelepiped metal member 501 and fixed with screws or the like. Thereafter, the wiring boards 505 and 506 are overlapped and sandwiched and fixed between the wiring board holding portion 504 and the substantially rectangular parallelepiped metal member 501, and the predetermined wiring is connected through the through-hole 532, thereby completing the accommodation.
[0050]
In the housing method described above, the gap between the housing portion 514 formed in the substantially rectangular parallelepiped metal member 501 and the high-frequency circuit board 507 is bridged by the metal conductor 516 on the wiring board 505. Furthermore, by reducing the size of the openings 520 and 525 formed in the wiring boards 505 and 506 on the side of the wiring board 505 on which the planar circuit wiring 521 is formed, the end of the planar circuit wiring 521 is exposed from the wiring board 506. .
[0051]
With such a structure, the planar circuit wiring 521 having a strip line structure sandwiched between the metal conductors 516 and 526 on the wiring boards 505 and 506 is an exposed portion, and the metal conductor 516 on the wiring board 505 and the planar circuit wiring 521 are exposed. It is possible to connect to the active elements 534a and 534b on the high-frequency circuit board 507 with metal thin wires. In this way, the change in characteristic impedance is small and the reflection of the connection portion can be reduced compared to the case where the gap between the storage portion 514 and the high-frequency circuit board 507 is connected by a thin metal wire.
[0052]
As described above, according to the fourth embodiment, the small-sized waveguide filter, the circular waveguide antenna, and the high-frequency circuit board are integrated to achieve a significant reduction in size and thickness of the high-frequency unit. In addition, the manufacturing method is simple and the adjustment process is not required, so that the cost of the high-frequency unit can be reduced. In addition, it was possible to reduce the reflection of the connection points with fine metal wires and form a high-frequency unit with low transmission loss. Therefore, it is possible to obtain the effects of future miniaturization of millimeter-wave and quasi-millimeter-wave radios, improvement of circuit characteristics, and price reduction.
[0053]
The preferred embodiments of the 90-degree bend waveguide, the waveguide filter element, and the high-frequency circuit unit according to this embodiment have been described above with reference to the accompanying drawings. However, the present invention is not limited to this example. . It will be obvious to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.
[0054]
In the third embodiment, a high-frequency unit having a patch antenna using a planar circuit has been described, and in the fourth embodiment, a high-frequency unit having a circular waveguide antenna has been described. However, the antenna shape is not limited to these, and antennas of various shapes can be used.
[0055]
For example, for the purpose of thinning, an antenna using a radial waveguide having a radio wave radiation slit in one conductor of a double-sided board composed of two conductors sandwiching a dielectric and having a power supply port for the antenna in the other conductor. Can be used. By adopting a structure in which one opening of the waveguide type filter element shown in the second embodiment is directly connected to the power supply port of this antenna, the conduction as shown in the third and fourth embodiments is achieved. The wave tube / planar circuit conversion section and the structural members necessary for holding the wiring board can be eliminated.
[0056]
【The invention's effect】
As described above, according to the present invention, a groove is formed in a substantially rectangular parallelepiped metal member, and a metal member having a vertical surface and a 45-degree tapered surface is fitted into the orthogonal portion of the waveguide orthogonal to the groove. Therefore, it is possible to easily obtain a small 90-degree bend type waveguide having good reflection characteristics. By integrating the filter element and the antenna using the 90-degree bend type waveguide, it is possible to reduce the cost and size. A high-performance waveguide filter element and a high-frequency circuit unit can be obtained.
[Brief description of the drawings]
1A and 1B are explanatory views showing a 90-degree bend waveguide according to a first embodiment, wherein FIG. 1A is an explanatory view schematically showing the entire structure, and FIG. It is explanatory drawing which shows a part in detail.
FIG. 2 is an explanatory diagram for comparing transmission characteristics of a 90-degree bend portion of the 90-degree bend waveguide according to the first embodiment with a conventional 90-degree bend portion.
FIGS. 3A and 3B are explanatory views showing a filter element according to a second embodiment, FIG. 3A is an explanatory view schematically showing the entire structure, and FIG. 3B is an explanatory view showing the structure of a filter unit; FIGS. It is.
4A and 4B are explanatory views schematically showing the overall structure of a high-frequency unit according to a third embodiment, wherein FIG. 4A is an explanatory view showing the arrangement of each member, and FIG. 4B is a filter element section; It is explanatory drawing which shows.
FIGS. 5A and 5B are explanatory views schematically showing the entire structure of a high-frequency unit according to a third embodiment, FIG. 5C is an explanatory view showing one wiring board, and FIG. 5D is the other wiring; It is explanatory drawing which shows a board.
FIG. 6 is an explanatory diagram schematically showing a wiring board pressing portion of a high frequency unit according to a third embodiment.
7A and 7B are explanatory views schematically showing the overall structure of a high-frequency unit according to a fourth embodiment, wherein FIG. 7A is an explanatory view showing the arrangement of each member, and FIG. 7B is a filter element section; It is explanatory drawing which shows.
FIGS. 8A and 8B are explanatory views schematically showing the entire structure of a high-frequency unit according to a fourth embodiment, FIG. 8C is an explanatory view showing one wiring board, and FIG. 8D is the other wiring; It is explanatory drawing which shows a board.
FIGS. 9A and 9B are explanatory views schematically showing the entire structure of a high-frequency unit according to a fourth embodiment, FIG. 9E is an explanatory view showing a wiring board pressing portion, and FIG. 9F is a high-frequency circuit board; It is explanatory drawing which shows.
FIG. 10 is an explanatory diagram showing a high-frequency circuit board housing portion of a high-frequency unit according to a fourth embodiment.
FIG. 11 is an explanatory diagram showing a millimeter waveband radio circuit device according to the prior art.
FIG. 12 is an explanatory diagram showing a 90-degree bend portion of a 90-degree bend waveguide according to the prior art.
[Explanation of symbols]
101 cuboid metal member
102a metal member
102b Metal member
103 metal plate

Claims (12)

In a 90-degree bend waveguide that bends the propagation direction of radio waves by 90 degrees;
A groove corresponding to the tube diameter of the first waveguide is formed on the surface, an opening is formed on the back surface perpendicular to the groove, and the second waveguide has the same tube diameter as the first waveguide. A substantially rectangular parallelepiped first metal member formed with a wave tube;
An end portion has a 45-degree tapered surface, and the 45-degree tapered surface faces the opening of the second waveguide at an orthogonal portion between the groove and the second waveguide. , A second metal member fitted in the groove;
A third metal member covering the groove and forming the first waveguide;
A 90-degree bend waveguide. The second metal member fitted in the groove has a vertical length of about 0.202 L connected to the second waveguide at the end when the short side length of the cross section of the waveguide is L. The 90-degree bend waveguide according to claim 1, wherein a 45-degree tapered surface is formed with the surface remaining. In a waveguide filter element in which a filter portion and a 90-degree bend waveguide are integrally formed;
A groove corresponding to the tube diameter of the first waveguide is formed on the front surface, and a predetermined partition forming the filter portion is formed in the groove, and an opening is formed on the back surface at least one end of the groove perpendicular to the groove. , A substantially rectangular parallelepiped first metal member formed with a second waveguide having the same tube diameter as the first waveguide;
An end portion has a 45-degree tapered surface, and the 45-degree tapered surface faces the opening of the second waveguide at an orthogonal portion between the groove and the second waveguide. , A second metal member fitted in the groove;
A third metal member covering the groove and forming the first waveguide and the filter portion;
A waveguide type filter element comprising: The second metal member fitted in the groove leaves a vertical surface having a length of about 0.202 L connected to the waveguide at the end when the short side length of the waveguide cross section is L. 4. The waveguide filter element according to claim 3, wherein a tapered surface of 45 degrees is formed. In a high-frequency circuit unit in which a waveguide filter element and an antenna are integrally formed;
A groove corresponding to the diameter of the first waveguide on the surface and a predetermined partition forming a filter part in the groove are formed, and at least one end of the groove is provided with an opening on the back surface orthogonal to the groove, A substantially rectangular parallelepiped first metal member on which a second waveguide having the same tube diameter as the first waveguide is formed;
An end portion has a 45-degree tapered surface, and the 45-degree tapered surface faces the opening of the second waveguide at an orthogonal portion between the groove and the second waveguide. , A second metal member fitted in the groove;
A third metal member covering the groove and forming the first waveguide and the filter portion;
A wiring board formed on the back surface of the first metal member, on which an antenna for transmitting and radiating radio waves output from the opening is formed;
A high-frequency circuit unit comprising: The second metal member fitted in the groove has a vertical length of about 0.202 L connected to the second waveguide at the end when the short side length of the cross section of the waveguide is L. 6. The high frequency circuit unit according to claim 5, wherein a 45-degree tapered surface is formed with the surface remaining. Arranged on the back surface of the first metal member, connected to the wiring board by a thin metal wire, and transmits an output signal to the waveguide type filter element through a planar circuit / waveguide converter formed on the wiring board. The high-frequency circuit unit according to claim 5, further comprising a high-frequency circuit board that performs processing. A high-frequency circuit housing portion for mounting the high-frequency circuit board is formed on the back surface of the first metal member, and the mounting surface of the high-frequency circuit board forms substantially the same surface as the back surface of the first metal member, The high-frequency circuit unit according to claim 7, wherein a gap between the high-frequency circuit board and the back surface of the first metal member is bridged by a metal conductor formed on the wiring board. 9. The high-frequency circuit unit according to claim 5, further comprising a fourth metal member that sandwiches the wiring board with the first metal member. 10. The high-frequency circuit unit according to claim 5, wherein the antenna is a patch antenna including a planar circuit formed on the wiring board. The antenna is an antenna having a structure that is guided to at least one radiating waveguide formed in the fourth metal member through a feeding line including a planar circuit formed on the wiring board. Item 10. The high-frequency circuit unit according to any one of Items 5, 6, 7, 8, and 9. The antenna according to any one of claims 5, 6, 7, 8 and 9, wherein the antenna is a radial waveguide formed of two conductors sandwiching a dielectric formed on the wiring board. The high frequency circuit unit described in 1.

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