JPH0352303A - High frequency power amplifier - Google Patents

Abstract

PURPOSE:To reduce leakage of a radio wave from a case by integrating a side wall and a bottom plate, forming a waveguide integrally further and adhering a radio wave absorbing member or a conductive tape so as to cover gaps between comb-line partition plates. CONSTITUTION:Comb-line partition plates 23A-23C and 23D-23F are projected from opposite side walls 21b to a metal-made case in which a bottom plate 21a, a side wall 21b and a waveguide 21c are integrated. High frequency components such as a FET are mounted on a microstrip line of a high frequency circuit board 25 and the microstrip line is prolonged through the gap between the partition plates 23A-23C and 23D-23F. Radio wave absorbing members 37A-37C are adhered to cover the comb-line partition plates 23A-23C and 23D-23F respectively. Since the bottom plate and the side wall are integrated and the waveguide is formed integrally, the leakage of a radio wave from the case is very small.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a high frequency power amplifier. Conventional Technology In recent years, with the launch of broadcasting satellites and communication satellites, the development and production of high-frequency circuit devices that make up satellite broadcasting receivers and communication devices using microwave bands has become active.
The importance of high frequency power amplification devices constituting the communication equipment is increasing. However, the quality has improved. While cost rationalization is being called for, the frequency band used in this type of high-frequency power amplifier is extremely high, ranging from several GHz to several tens of GHz, and requires extremely large output power gain.
Characteristics vary widely depending on the assembly state.

Additionally, the radio waves leaking from the amplifier housing were large, and had a significant impact on other units. Therefore, it is extremely important to stabilize quality and rationalize costs in preparation for mass production. Conventionally, this type of high-frequency power amplifier has had a configuration as shown in FIG. In FIG. 6, 1 is a metal bottom plate, 2 is a metal side wall having partition plates 3A to 3C, and 4 is a metal lid. 5 is a high frequency circuit board, and FETs 6A, 6B, 7A, 7B . High frequency components such as chip components 8A to 80 are mounted, and screws 9
It can be attached to the bottom plate 1 with. The coaxial connector 10 is attached to the side wall 2 by screws 11, and the coaxial connector 1
The center conductor 12 of 0 is soldered to the microstrip line 2 of the board 5, and this side wall 2 is connected to the lid 4 with screws 13.
Each component on the microstrip line of the board 5 is housed in each room in the side wall 2 partitioned by the partition plate 3. A metal support 14 is housed in a cylindrical dielectric material 15, is inserted into a waveguide 16 attached to the bottom plate 1 together with the cylindrical dielectric material 15 through the bottom plate 1, and is inserted between the waveguide 16 and the waveguide 16. It has an antenna pin for mode conversion, and this antenna pin is connected to the board 5.
It can be attached to the microstrip line by soldering. The operation of a conventional high-frequency amplifier configured in this way will be explained. The signal input from the coaxial connector IO is transmitted on the strip line formed on the board 5. The signals are amplified by FETs 6A, 6B, 7A, and 7B, converted into waveguides, and outputted from the waveguide 16. Usually, the high frequency circuit board 5 is made of polytetrafluoroethylene, which has low dielectric loss and is easy to adjust using sudab. The dielectric constant ε1 of the polytetrafluoroethylene substrate is as small as 2.6, and radio wave radiation is large. Therefore, in order to prevent interference between FETs due to radio wave radiation, partition plates 3A to 3C are provided on the side wall 2. Radio wave absorbers may be attached to the partition plates 3A to 3C. Problems to be Solved by the Invention However, in such a conventional method, since the bottom plate 1 and the side wall 2 are separated, there is a problem that radio waves leak from the joint surface of the bottom plate 1 and the side wall 2, and have a negative impact on other devices. was there. In other words, although the joint surface between the bottom plate 1 and the side wall 2 is sufficiently surface-treated, due to the extremely large output, the final stage FE
Radio wave leakage near T could not be ignored. The present invention attempts to solve such problems, and aims to provide a high-frequency power amplification device with very little leakage of radio waves from the housing. Means for Solving the Problems In order to solve the above-mentioned conventional problems, the high frequency power amplification device of the present invention has an input terminal consisting of a coaxial connector, an output terminal consisting of a waveguide, and a microelectronic cable connected between the input terminal and the output terminal. The planar circuit is constructed from a strip line structure with a planar circuit. A comb-shaped partition plate is arranged between the transistors on both sides of the metal casing, and a radio wave absorber or conductive tape is pasted so as to pass between the comb-shaped partition plates facing each other. , the metal lid is covered from the top surface of the metal casing to provide shielding as a whole. Effects With the above configuration, the conventional side wall and bottom plate are integrated, and the waveguide is further formed integrally with this, so the gap between the side wall and the bottom plate and the gap between them and the waveguide are eliminated. Radio wave leakage from the metal casing is extremely reduced. In addition, by pasting radio wave absorbers or conductive tape between the comb-shaped partition plates, FE can be
Radio wave interference between Ts can be suppressed and deterioration of high frequency characteristics can be prevented. EXAMPLE An example of the present invention will be described below based on the drawings. FIG. 1 is an exploded perspective view of a high frequency power amplifier according to an embodiment of the present invention. In FIG. 1, 21 is a metal case in which a bottom plate 21a, a side M2lb, and a waveguide 21c are integrated, and comb-shaped partition plates 23A to 23G and 23D to 2
3F protrudes from the opposite side wall 2lb. The metal used is aluminum, which is lightweight and has good conductivity. 24 is the lid, which is made of aluminum. 25 is a high frequency circuit board made of a polytetrafluoroethylene board with low dielectric loss, and FET26A, 26 is placed on the microstrip line of the board 25.
B, 27A, 27B, chip parts 28A to 28C
High frequency components such as the following are mounted, and are attached to the bottom plate 21a of the case 2l with screws 29. At this time, the microstrip line is connected to partition plates 23A to 23G and 23D.
It extends through the gap between ~23F and 23F. The coaxial connector 30 is attached to the side wall 2lb of the case 21 with screws 31, the center conductor 32 of the coaxial connector 30 is soldered to the microstrip line of the board 25, and then the lid 2
4 is fixed to the upper surface of the side wall 2lb of the case 2l with screws 33. A copper rod 34 is housed in a cylindrical dielectric material 34 made of a polytetrafluoroethylene cylinder, and is inserted into the waveguide 21c of the case 2l through the bottom plate 21, and is inserted between the waveguide 21c and the waveguide 21c. It has an antenna bin for mode conversion, and is fixed to the microstrip line of the board 25 by soldering. This board 25 is fixed to the bottom plate 21a of the case 21 after the antenna bin is attached. Reference numerals 37A to 31G are radio wave absorbers, which are pasted across the gaps between the comb-shaped partition plates 23A to 23G and 23D to 23F, respectively. The operation of the high frequency amplification device configured as described above will be explained below. A signal input from the coaxial connector 30 is transmitted on the microstrip line formed on the substrate 25, amplified by FETs 26A, 26B, 27A, and 27B, and subjected to mode conversion, that is, a coaxial waveguide conversion, and then transferred to the microstrip line formed on the case 21. The signal is output from the waveguide 21c. In the above operation process, the amplified signal hardly leaks from any part other than the waveguide 21c which is the output port, and the comb-shaped partition plates 23A to 23C of the case 21
Radio wave absorbers 37A to 37 pasted between 3D and 23F
By G, FET26A, 26B, 27A
, 27B is also suppressed, and a high-frequency power amplification device with high performance and little radio wave leakage can be obtained. Next, another embodiment of the present invention will be explained with reference to FIG. The difference from FIG. 1 is that the waveguide attachment direction of the output terminal is perpendicular to the microstrip line. In FIG. 2, 41 is an aluminum case in which a bottom plate 41a, a side wall 4lb, and a waveguide 41c are integrated, and the waveguide 41c is attached to the side wall 4lb, and its mounting direction is fixed to the bottom plate 41a. High frequency circuit board 4
The direction is perpendicular to the microstrip line of 5. 43A to 43D, 43E to 43H are case 4
Partition plate protruding from the side wall 4lb of 1, 44 is the side wall 4l
46A, 46B, and 48A to 48F are high-frequency circuit boards 45 made of bolite rubber fluoroethylene;
High-frequency components such as FETs and chip components mounted on microstrip lines. 49 connects the substrate 45 to the bottom plate 4
The screw 50 is fixed to the case 51 with the screw 51.
A coaxial connector, 52, attached to the bottom plate 41a of
is the center conductor of the coaxial connector 50, and 53 is a screw that fixes the lid 44 to the upper surface of the side wall 4lb of the case 4l. Also,
54 constitutes an antenna bin, a copper rod is housed in a cylindrical dielectric material 55 made of a polytetrafluoroethylene cylinder and inserted into the waveguide 41c, and 57A to 57D are comb-shaped partition plates 43A to 43D. This is a radio wave absorber that is pasted between 43D and 43H. Also 58A~58
E is a high output FET, which is directly fixed to the bottom plate 41a of the case 41 with screws 59A to 59H. Here, the main points of this embodiment will be explained.

FIGS. 3(a) and 3(b) are partial perspective views of the present embodiment and the conventional example after assembly, with the partition plate portion taken out. The signal amplified by the FET is transmitted on the microstrip line, but at the same time radio wave radiation is also generated. Radio wave interference between FETs 6 and 7 due to this radio wave radiation acts in the direction of hindering the performance of the FETs, so normally
A partition plate 3 is provided between the ET 6 and the FET 7 perpendicularly to the signal line as shown in FIG. Intimidation, F
Radio wave interference between ET6 and ET7 was suppressed. however,
In this structure, the side wall 1 and the bottom plate 2 had to be separated due to board mounting, which caused radio wave leakage from the casing and adversely affected other units. The present embodiment takes this point into account, and as shown in FIG. 3(a), the bottom plate and side walls are integrated to form a structure that suppresses leakage of radio waves from the casing. In FIG. 3(a), in order to insert the high-frequency circuit board 25 into the case 21, a part of the partition plate 23 is cut, and a radio wave absorber 37 is pasted across the cut part of the partition plate 23. It is being This radio wave absorber 37 is a waveguide structure 6 shown in FIG. 3(b).
This is a means for simply deriving the characteristics of No. 1, and is attached so as to have the same dimensions as the waveguide structure 6l. Also,
The radio wave absorber 37 also has the function of absorbing radio wave radiation, resulting in a high frequency amplification device with even better high frequency characteristics. 4 and 5 show conductive tape 6 instead of the radio wave absorber 37.57 in FIGS. 1 and 2.
3.64 is used.

Effects of the Invention As described above, according to the present invention, the bottom plate and the side wall have an integral structure, and furthermore, the waveguide is integrally formed therein, so that high frequency power can be generated with very little radio wave leakage from the housing. An amplification device can be obtained.

Furthermore, by pasting a radio wave absorber across the comb-shaped partition plates of the housing, radio wave interference between FETs can be suppressed, making it possible to obtain a high frequency power amplification device with good high frequency characteristics. In addition, since the bottom plate and side walls have an integrated structure, it is possible to reduce the number of molds during mass production, saving mold costs and eliminating the need for surface treatment of the joint surfaces of the bottom plate and side walls. This reduces processing costs. Furthermore, there is no need to screw the bottom plate and side walls together, which reduces assembly man-hours, stabilizes quality, and eliminates the need for related jigs.

[Brief explanation of drawings]

1 and 2 are exploded perspective views of a high frequency power amplifier according to an embodiment of the present invention, and FIGS. 3(a) and 3(b) respectively.
4 and 5 are respectively exploded perspective views of high frequency power amplifiers according to other embodiments of the present invention, and FIG. FIG. 2 is an exploded perspective view of a conventional high-frequency power amplifier. 21.41...Case, 21a, 41a
-Bottom plate, 2lb, 4lb-...side wall, 21c, 41c-
Waveguide. 23.23A-23D, 43A-43H...
Partition plate, 24. 44...lid, 25.45...
High frequency circuit board, 26. 26A, 26B, 4
6A, 46B, 27, 27A, 27B...FE
T, 28A to 28C, 48A to 48F... Chip parts, 29, 49, 33, 53,... Screws, 30.50.
...Coaxial connector, 34. 54...Copper rod, 35
．． 55... Cylindrical dielectric material, 37. 37A-37G
, 57A to 57D... Radio wave absorber, 58A to 58E.
・・High output FET, 63A~63C, 64A~64D
...Conductive tape.

Claims (1)

[Claims] 1. It has an input terminal having a coaxial connector structure and an output terminal having a waveguide structure, and a planar circuit having a microstrip line structure is configured between the input terminal and the output terminal, and the waveguide is integrated. The planar circuit is provided on the bottom plate of one box-shaped metal casing, and partition plates are installed from both side walls of the metal casing between the respective high-frequency power amplification transistors mounted on the planar circuit. High-frequency power is arranged so as to protrude in a comb shape, and a radio wave absorber or conductive tape is pasted between the comb-shaped partition plates facing each other, and a metal lid is covered from the top surface of the metal casing to shield the entire body. Amplifier.