JPH05175712A - Power combiner and distributor - Google Patents

Abstract

PURPOSE:To obtain a miniaturized power combiner and distributor excellent in isolation characteristic. CONSTITUTION:The top plate 14a of a case 14 constituting a radial line 5 is constituted obliquely from almost a center provided with a central coaxial terminal 1a toward the outer peripheral part so as to be close to a bottom plate 14b gradually. Furthermore, adjacent converters 7 constituted of a strip line connected to a peripheral coaxial terminal 1c provided on the side plate 14c of the top plate 14 are connected by two or more resistors 8, 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power combiner / distributor mainly used in the microwave band and millimeter wave band.

[0002]

2. Description of the Related Art In recent years, traveling wave tube amplifiers (TWTA) have become more reliable and more reliable in microwave and millimeter wave communication.
Replacement of small semiconductor amplifiers is in progress. However, since the semiconductor currently used has a small output by itself, a power combiner / distributor is required. An example of a power combiner / distributor that combines and distributes the outputs of many amplifiers is shown in FIG. The figure shows `` Wideband Microwave Pow
er Divider / Combiner Using Conical-Radial Line ",
S. Nogi, et al., The 3rd Asia-Pacific Microwave Confere
nce Proceedings, (Tokyo) No. 7-2, pp121-124, 1990 is a schematic configuration diagram of a power combiner / distributor for performing 8 combiner / distributor, where (a) is a plan view and (b) is Is a sectional view. In the figure, 1a and 1b are a central coaxial terminal and peripheral coaxial terminals, 2a and 2b are conversion elements for a coaxial line and a radial line, 3 is a radial line portion, 4 is a top plate 4a, a bottom plate 4b, a side plate 4c. It is a case formed in a more circular box shape.

Next, the operation will be described. Coaxial terminal 1a
The incident wave from the TE is coaxial as shown in the electric field distribution in FIG.
The M mode is gradually converted to the radial mode by the central conversion element 2a. The wave converted to the radial mode propagates concentrically from the center toward the outside, and is similarly converted from the radial mode to the coaxial T by the peripheral conversion element 2b.
Converted to EM mode, the same phase on the eight coaxial terminals 1b,
Output with equal amplitude. Since the impedance of the radial line changes depending on the distance from the center, it is necessary to determine the position of the conversion element 2b to have an appropriate impedance in order to obtain good reflection characteristics at the coaxial terminal 1b. The impedance Z of the radial line at the position of a distance r from the center is expressed by the following equation. Z = Hη / (2πr) (1) where H is the height of the radial line and η is the intrinsic impedance of the medium, which is 377Ω in this case. Assuming that the number of combining / distributing is N and the characteristic impedance of the coaxial terminal 1b is Z ₀₁ , the position where the peripheral conversion element 2b should be provided is the position where the characteristic impedance Z ₀₂ = (Z ₀₁ / N) Ω of the radial line. Therefore, the distance R from the center to the position where the conversion element 2b should be provided can be obtained from the equation (1) by the following equation. R = NHη / (2πZ ₀₁ ) (2) The distance R increases as the number of combined / distributed N increases, and the size of the power combiner / distributor increases. 9 of the above-mentioned document
According to the experimental result of the number of composition / distribution N = 8 in the GHz band,
In order to suppress the generation of the higher-order mode, H = 5 mm, the characteristic impedance of the coaxial terminals 1a and 1b is Z ₀₁ = 50Ω, and R = 47.8 mm. At this time, loss 0.
The worst value of isolation is 5 dB and 7 dB.

[0004]

Since the conventional power combiner / distributor is configured as described above, it has a feature that outputs of a large number of amplifiers can be combined / distributed with low loss at a time. As is clear from 1), the distance R increases as the number of combining / distribution N increases, that is, the power combining /
There was a problem that the distributor became large. In addition, the above-mentioned conventional power combiner / distributor has a worst isolation value of 7
Since it is dB, there is a problem that sufficient isolation cannot be obtained.

The present invention has been made to solve the above problems, and an object thereof is to provide a power combiner / distributor which can be made compact and which can obtain sufficient isolation. To do.

[0006]

In the power combiner / distributor according to claim 1 of the present invention, the top plate of the case forming the radial line is gradually inclined from the center toward the outer peripheral side so as to approach the bottom plate. Configured as

A power combiner / distributor according to claim 2 of the present invention is a converter constituted by a strip line of a predetermined length connected to a plurality of coaxial terminals provided on an outer peripheral side plate of a case constituting a radial line. Is used to connect the adjacent converters to each other with two or more resistors.

[0008]

In the power combiner / distributor according to the first aspect of the present invention, the distance from the center to the outer peripheral side where the coaxial terminal of the case forming the radial line is provided can be shortened, and the device can be made compact.

In the power combiner / distributor according to the second aspect of the present invention, the isolation characteristic is further improved by the two or more resistors.

[0010]

EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a power combiner / distributor, where (a) is a plan view and (b) is a sectional view. In the figure, 1a is a central coaxial terminal, 1b is a peripheral coaxial terminal, 2a is a conversion element facing the central coaxial terminal 1a, 2
Reference numeral b is a conversion element facing the peripheral coaxial terminal 1b, and 14 is a circular box-shaped case constituting the radial line portion 5, which is a bottom plate 14b and a top plate 14 facing the bottom plate 14b.
a, a side plate 14c that covers the bottom plate 14b and the top plate 14a.
Consists of The central coaxial terminals 1a are provided substantially at the center of the top plate 14a, and the peripheral coaxial terminals 1b are provided on the outer peripheral side of the top plate 14a at equal intervals (eight in this case).
The feature of the present embodiment is that the radial line portion 5 is configured by gradually bringing the top plate 14a closer to the bottom plate 14b from the center to the outer peripheral side and inclining.

According to the above structure, since the height of the radial line portion 5 becomes lower toward the outer peripheral side of the case 4, the impedance at the distance R from the center of the case is constant when the height H is constant. The characteristic impedance at the position where the peripheral conversion element 2b is provided is (50
The distance R which is equal to / N) becomes smaller than in the case where the height H is constant as in the conventional case (see the equation (2)). Therefore,
Even if the distribution number N is large, there is an advantage that the device can be made smaller than the conventional one.

Example 2. 2A and 2B are schematic configuration diagrams of a power combiner / distributor according to another embodiment of the present invention. FIG. 2A is a plan view and FIG. 2B is a sectional view. In this embodiment, the peripheral coaxial terminal 1b is provided on the side plate 4c of the case 4 having the conventional structure, and the converter 7 connected to the coaxial terminal 1b is formed by a strip line. In the figure, 1c is a peripheral coaxial terminal, 7
Is a converter, and 8 and 9 are chip-shaped resistors. The converter 7 is composed of a strip line and converts from the radial mode to the coaxial TEM mode. The length is about 1/4
It is an odd multiple of the wavelength. The resistors 8 and 9 are connected to both ends of the adjacent converter 7, and in particular, the resistor 9 is connected to the radial line side slightly out of the converter 7. That is, two adjacent resistors of the converter 7 are connected to two or more resistors 8,
9 are connected at two or more points.

Now, for convenience, a case where the power combiner / divider of FIG. 2 is used as a power combiner will be described. If the input power of any one of the eight peripheral coaxial terminals 1c is lost or becomes small, the voltage and current excited by the converter 7 connected to that terminal are generated by the adjacent converters. Since they are different, a current flows through the connected resistors 8 and 9, and the difference acts between them. That is, it operates so as to increase the isolation. Therefore, the isolation is better than when there is only one resistor. But,
The voltages are not completely the same, and not only the fundamental wave but also higher-order modes are excited in the radial line portion 3. in this case,
Since the resistor 9 is slightly projected and connected to the radial line portion 3, the generated higher order mode can be absorbed.

Example 3. 3 and 4 show another embodiment of the present invention (more specifically, a modification of the second embodiment).
In which a ring-shaped dielectric is used. 3 is a plan view of a main part inside the case, and FIG. 4 is a perspective view of the main part. In each figure, 10 is a ring-shaped dielectric, 11
Is a resistor provided on the dielectric 10, and 12 is a conductor film provided on the dielectric 10. Since the resistor 11 is provided directly on the dielectric, the number of parts is smaller than that of the resistor shown in FIG. 2, and if the heat conduction of the dielectric 10 is good, it can be applied to the case of high power.

Example 4. FIG. 5 shows a cross-sectional view of a power / distributor in which the configurations of FIGS. 1 and 2 described above in the present invention are combined. According to this configuration, both the downsizing of the device and good isolation characteristics are achieved as described above. Is obtained.

[0016]

As described above, according to the power combiner / distributor of the present invention, the top plate of the case forming the radial line has a structure in which the height gradually decreases from the center to the outer peripheral side. It is possible to obtain good isolation characteristics because the adjacent converters, which are composed of a strip line of a predetermined length and are connected to a plurality of peripheral coaxial terminals, are connected by two or more resistors. effective.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a power combiner / divider showing an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a power combiner / divider showing another embodiment of the present invention.

FIG. 3 is a configuration diagram of a main part of a power combiner / distributor showing another embodiment of the present invention.

FIG. 4 is a perspective view of an essential part of FIG.

FIG. 5 is a sectional view of a power combiner / divider showing another embodiment of the present invention.

FIG. 6 is a schematic configuration diagram showing an example of a conventional power combiner / divider.

FIG. 7 is an electric field distribution diagram of a conversion element portion of a conventional power combiner / distributor.

[Explanation of symbols]

 1a Central coaxial terminal 1b, 1c Peripheral coaxial terminal 2a, 2b Conversion element (converting means) 5 Radial line part 7 Strip line type converter 8, 9 Resistor 14 Case 14a Top plate 14b Bottom plate 14c Side plate

Claims (2)

[Claims] 1. A case comprising a bottom plate and a top plate facing the bottom plate, a central coaxial terminal provided substantially at the center of the top plate, and a plurality of peripheral coaxial terminals provided on the outer peripheral side of the top plate. And a converter provided on the bottom plate so as to face the central coaxial terminal, and a converter provided on the bottom plate so as to face the peripheral coaxial terminal. An electric power combiner / distributor characterized in that the top plate is gradually brought closer to the bottom plate from the center to the outer peripheral side to have an inclination. 2. A case comprising a bottom plate and a top plate facing the bottom plate, a central coaxial terminal provided substantially in the center of the top plate, and a plurality of peripheral coaxial terminals provided on the outer peripheral side plate of the top plate. And a conversion means provided on the bottom plate so as to face the central coaxial terminal, and a converter formed of a plurality of strip lines each having a predetermined length and located in the case and connected to the peripheral terminals, respectively. An electric power combiner / distributor having the above-mentioned converter, wherein adjacent ones of the converters are connected by two or more resistors.