JP3971326B2 - High frequency power combiner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high-frequency power combiner that combines high-frequency power for transmission and supplies power to an antenna.
[0002]
[Prior art]
For example, antenna transmission power in television broadcasting or the like requires very large power, and a single power amplifier is often insufficient. For this reason, conventionally, high-frequency power output from a transmitter is input to a plurality of power amplifying devices and amplified, and the output of each amplifying device is combined with a high-frequency power combiner to obtain predetermined power, and then fed to the antenna. (For example, refer nonpatent literature 1.).
[0003]
Specifically, the conventional high-frequency power combiner is configured as shown in FIG. In FIG. 6, reference numeral 11 denotes a case main body of the high-frequency power combiner 10, which is provided with an upper lid 12 on the upper surface and a lower lid 13 on the lower surface. A plurality of, for example, four input terminals 14 a to 14 d are mounted on the front surface of the case body 11. Each of the input terminals 14 a to 14 d includes an outer conductor 15 and a center conductor 16. Although not shown, the output of the transmitter is amplified and input to each of the input terminals 14a to 14d by four power amplifiers. In the case body 11, input coaxial cables 17a to 17d are provided. One end thereof is connected to each of the input terminals 14a to 14d. Further, in the case main body 11, a power combining unit 18 is provided on the front end wall. The power combiner 18 includes a plurality of, in this example, four feed points 19 around the power combiner 18, and the other ends of the input coaxial cables 17 a to 17 d are connected to the feed points 19. In this case, the input coaxial cables 17 a to 17 d are in a state of being disposed in the air inside the case body 11.
[0004]
Further, an output coaxial composite tube 21 is coupled to the output side of the power combiner 18, and the front end side thereof is led out through the rear end wall of the case body 11. An output terminal 22 is formed at the tip of the output coaxial composite tube 21 led out from the rear end wall of the case body 11. The output terminal 22 includes an outer conductor 23 and a center conductor 24. The transmission power extracted from the output terminal 22 is supplied to a transmission antenna (not shown).
[0005]
The high-frequency power combiner configured as described above synthesizes the transmission power from each power amplifier input to the input terminals 14a to 14d by the input coaxial cables 17a to 17d to the power combiner 18 and combines them. Electric power is output via the output coaxial composite tube 21 and fed to the transmitting antenna from the output terminal 22.
[0006]
[Non-Patent Document 1]
Broadcast Technology Sosho “Broadcaster”, Japan Broadcasting Publishing Association, issued April 20, 1983, p. 142-147
[0007]
[Problems to be solved by the invention]
In the conventional high-frequency power combiner 10, it is desirable that the input coaxial cables 17 a to 17 d for inputting the transmission power to the power combiner 18 are thick cables having sufficient power passing ability. It is difficult to use because of cable bending tolerance and space. For this reason, the input coaxial cables 17a to 17d corresponding to the space of the high-frequency power combiner 10 are used, but heat is generated by the passing power. This heat generation causes deterioration of the performance of the connection portions of the input coaxial cables 17a to 17d and the cable itself, and also causes burnout at a high temperature.
[0008]
Conventionally, this type of high-frequency power combiner 10 is installed together with a power amplifying device in an air duct that is forcibly air-cooled by a fan, and heat generated by the input coaxial cables 17a to 17d is diffused by the wind of the air duct.
[0009]
However, in recent years, the cooling method of the power amplifying device has changed, and instead of cooling with an air duct, a centralized cooling method for directly cooling the power amplifying device has been used, and the high frequency power combiner 10 is also arranged outside the air duct. It became so. For this reason, the high frequency power combiner 10 cannot be forcibly cooled, and a large-diameter cable must be used to prevent heat generation of the input coaxial cables 17a to 17d, resulting in an increase in size. It was.
[0010]
The present invention has been made to solve the above problems, and can efficiently dissipate heat from the input coaxial cable without using forced cooling, and reliably prevents performance deterioration due to heat generation and burnout of the cable itself. An object of the present invention is to provide a high-frequency power combiner that can be obtained.
[0011]
[Means for Solving the Problems]
A high-frequency power combiner according to the present invention includes a case, a plurality of input terminals to which high-frequency power for synthesis is provided arranged on one side surface of the case, and a power combiner provided in the case. A plurality of input coaxial cables of equal length connecting between each of the input terminals and the power combining unit, and an output coaxial combining tube that outputs the high-frequency power combined by the power combining unit to the outside , The input coaxial cable is fixed so as to abut along an inner surface of at least one other side surface excluding the one side surface, and a heat sink is provided outside the case on the abutted surface. It is characterized by.
[0012]
According to said structure, the heat which generate | occur | produces with an input coaxial cable can be efficiently spread | diffused outside via the heat sink provided in the case. Therefore, it is possible to reliably prevent deterioration of electrical characteristics due to heat generation and damage to the input coaxial cable itself, it is possible to withstand large passing power even with a small-diameter input coaxial cable, and it is possible to reduce the size of the high-frequency power combiner. .
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1A and 1B show a configuration of a high-frequency power combiner according to an embodiment of the present invention, in which FIG. 1A is a front view, FIG. 1B is a plan view with a part of an upper lid cut away, and FIG. FIG. 2 is a front view showing the case front partly cut away in the same embodiment, and FIG. 3 is a cross-sectional view taken along line AA in FIG. FIG. 4 is an enlarged view showing a fixed portion of the input coaxial cable.
[0014]
1 to 3, reference numeral 31 denotes a case of the high-frequency power combiner 30. For example, an upper lid heat sink 33 is provided on the upper surface of the case body 32, and a bottom lid heat sink 34 is provided on the bottom surface. The upper lid heat sink 33 and the bottom lid heat sink 34 are made of a material having good thermal conductivity and thermal diffusion, such as aluminum, and a plurality of radiating fins 35 and 36 are integrally formed on the outside at predetermined intervals. The heat radiation fins 35 and 36 are provided, for example, so as to face in the vertical direction to enhance the heat radiation effect.
[0015]
A plurality of, for example, four input terminals 37 a to 37 d are mounted on the front surface of the case 31. Each of the input terminals 37 a to 37 d includes an outer conductor 38 and a center conductor 39. High frequency power output from a transmitter (not shown) is amplified and input to each of the input terminals 37a to 37d by four power amplifiers.
[0016]
Further, in the case 31, input coaxial cables 41a to 41d are provided as feeder lines, and one ends thereof are connected to the input terminals 37a to 37d, respectively. As the input coaxial cables 41a to 41d, for example, semi-rigid cables whose outer conductors are made of copper pipe or steel pipe are used. Further, in the case 31, a power combiner 42 is provided on the front end wall.
[0017]
The power combiner 42 is made of a metal such as copper or brass, and a plurality of, for example, four feed points 43a to 43d are provided around the power combiner 42. The input coaxial cable is connected to each of the feed points 43a to 43d. The other ends of 41a to 41d are connected by, for example, soldering or brazing. In this case, the input coaxial cables 41a to 41d are brought into close contact with the inner surface of the top cover heat sink 33 or the bottom cover heat sink 34 as shown in FIG. A plurality of locations are fixed by screws or the like as appropriate. For example, the input coaxial cables 41 a and 41 b connected to the input terminals 37 a and 37 b are in close contact with the inner surface of the upper lid heat sink 33 and are appropriately fixed by the cable clip 44. Further, the input coaxial cables 41 c and 41 d connected to the input terminals 37 c and 37 d are brought into close contact with the inner surface of the bottom cover heat sink 34 and are appropriately fixed by the cable clip 44. The input coaxial cables 41a to 41d have the same length and are set so that the input terminals 37a to 37d have the same electrical characteristics such as input impedance and phase condition.
[0018]
By fixing the input coaxial cables 41a to 41d to the upper lid heat sink 33 and the bottom lid heat sink 34 with the cable clip 44 as described above, heat generated by the input coaxial cables 41a to 41d is efficiently dissipated. To do. In order to improve the heat dissipation effect for the input coaxial cables 41a to 41d, it is preferable to increase the width of the cable clip 44 and to increase the number of fixing points by the cable clip 44. Further, the cable clip 44 uses a copper plate or the like having a good thermal conductivity, and by using soldering or brazing together with the input coaxial cables 41a to 41d, the input coaxial cables 41a to 41d are connected to the heat sinks 33 and 34. Heat diffusion is more effective.
[0019]
An output coaxial composite tube 45 is coupled to the output side of the power combiner 42. The outer conductor of the output coaxial composite tube 45 is formed of a coaxial waveguide such as a copper tube or a brass tube, and the leading end of the outer conductor penetrates through the rear end wall of the case body 32 and is led out to the outside. An output terminal 46 is formed at the tip of the output coaxial composite tube 45 led out from the rear end wall of the case body 32. The output terminal 46 is formed of a coaxial waveguide and includes an outer conductor 47 and a center conductor 48. The transmission power extracted from the output terminal 46 is supplied to a transmission antenna (not shown).
[0020]
In the above-described configuration, a plurality of transmitter outputs, in this case, are amplified by four power amplifiers and input to the input terminals 37 a to 37 d of the high-frequency power combiner 30. The transmission power input to the input terminals 37a to 37d is supplied to the feeding points 43a to 43d of the power combining unit 42 via the input coaxial cables 41a to 41d, and is combined by the power combining unit 42. Then, the transmission output combined with the power combining unit 42 and having a predetermined power is output from the output coaxial combining tube 45 and fed from the output terminal 46 to the transmission antenna.
[0021]
When the transmission power is combined, heat generated in the input coaxial cables 41 a to 41 d is effectively radiated by the upper lid heat sink 33 and the bottom lid heat sink 34. Further, when the high frequency power combiner 30 is installed, the radiating fins 35 and 36 of the heat sinks 33 and 34 are installed so as to face in the vertical direction, so that the convection air easily rises from below to the heat sink 33, 34 can be naturally cooled (air cooled) more effectively. In addition, when the high frequency power combiner 30 cannot be installed in a specified state and the installation conditions are special, the radiation fins 35 and 36 of the heat sinks 33 and 34 are directed vertically in the installation conditions. May be set in advance.
[0022]
As described above, the input coaxial cables 41a to 41d are fixed to the inner surfaces of the upper lid heat sink 33 and the bottom lid heat sink 34 with the cable clip 44, whereby the heat generated by the input coaxial cables 41a to 41d is efficiently diffused to the outside. It is possible to prevent deterioration of electrical characteristics due to heat generation and damage to the input coaxial cables 41a to 41d themselves, and even a small-diameter input coaxial cable 41a to 41d can withstand large passing power. Miniaturization became possible.
[0023]
In the above embodiment, the case where the input coaxial cables 41a to 41d are directly fixed to the inner surfaces of the upper lid heat sink 33 and the bottom lid heat sink 34 with the cable clip 44 has been described. However, for example, as shown in FIG. A cable groove 51 may be provided on the inner surfaces of 33 and 34, and input coaxial cables 41 a to 41 d may be wired in the cable groove 51 and fixed by the cable clip 44.
[0024]
By providing the cable groove 51 and wiring the input coaxial cables 41a to 41d as described above, the contact area between the heat sinks 33 and 34 and the input coaxial cables 41a to 41d can be increased to further improve the heat dissipation effect. .
[0025]
Moreover, although the case where the heat sink was formed in the upper cover and the bottom cover of the case has been described in the above embodiment, it goes without saying that the heat sink may be formed on other surfaces.
[0026]
Moreover, although the case where 4 electric power was combined by input terminal 37a-37d was shown in the said embodiment, this invention is not limited to 4 terminal input, Other numbers of terminals, for example, 2 terminals, 3 terminals, 6 Even in the case where a plurality of terminals such as terminals are provided and synthesized, it can be carried out in the same manner as in the above embodiment.
[0027]
【The invention's effect】
As described above in detail, according to the present invention, a heat sink that releases heat of the case to the outside is provided in the case, and the input coaxial cable is fixed so as to be positioned along the inner surface of the case. The generated heat can be efficiently diffused to the outside by natural cooling, and it is possible to reliably prevent deterioration of electrical characteristics due to heat generation and damage to the input coaxial cable itself, and to withstand large passing power even with a small-diameter input coaxial cable. As a result, the power combiner could be miniaturized.
[Brief description of the drawings]
1A is a front view of a high-frequency power combiner according to an embodiment of the present invention, FIG. 1B is a plan view thereof, and FIG.
FIG. 2 is a front view showing the case front surface of the high-frequency power combiner with a part cut away in the embodiment;
FIG. 3 is a cross-sectional view taken along line AA in FIG.
FIG. 4 is an enlarged view showing a fixed portion of the input coaxial cable in the embodiment.
FIG. 5 is a diagram showing another example of fixing an input coaxial cable.
FIG. 6 is a perspective view showing a part of a case of a conventional high-frequency power combiner cut away.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 30 ... High frequency electric power combiner 31 ... Case 32 ... Case main body 33 ... Top cover heat sink 34 ... Bottom cover heat sinks 35, 36 ... Radiation fins 37a-37d ... Input terminal 38 ... Input terminal outer conductor 39 ... Input terminal center conductor 41a-41d ... input coaxial cable 42 ... power combining unit 43a-43d ... feed point 44 ... cable clip 45 ... output coaxial combining tube 46 ... output terminal 47 ... outer conductor 48 of output terminal ... center conductor 51 of output terminal ... cable groove

Claims (3)

A case, a plurality of input terminals to which synthesis high-frequency power is provided arranged on one side surface of the case, a power synthesis unit provided in the case, the input terminals and the power synthesis unit, A plurality of input coaxial cables of equal length that connect between each other, and an output coaxial composite tube that outputs the high-frequency power combined by the power combining unit to the outside, the input coaxial cable having the one side surface A high frequency power composition characterized in that it is fixed so as to be in contact with an inner surface of at least one other side surface except for a heat sink, and a heat sink is provided outside the case of the contact surface. vessel.   The high-frequency power combiner according to claim 1, wherein a semi-rigid cable is used as the input coaxial cable, and the fixing means is soldered or brazed.   The high frequency power combiner according to claim 1 or 2, wherein a cable groove is provided on an inner surface of the case, and the input coaxial cable is wired in the cable groove.

Images