JPH1168421A - Power mixing circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a circuit of a small size and a small transmission loss by constituting a center conductor of plural rat race circuits and providing a shape similar to the center conductor for an outer conductor to combine with the center conductor to make a dimension with desired impedance. SOLUTION: At a rat race (A) 2, an input from (1) is equally distributed to (2) and (3) and as (4) makes a short circuit port at this time, a signal does not pass through (4). Similarly, at rat races (B) 3 and (C) 4, an input from (1)' is equally distributed to (2)' and (3)' and an input from (1)" is equally distributed to (2)" and (3)". Namely, an input from (1) set to be 1 makes 1/4 at (2)', (3)', (2)" and (3)". At the time of thinking reversely due to a reversible circuit then, inputs from (2)', (3)', (2)" and (3)" are mixed and sent to (1). In addition, in order to form these operation, line length from each input/output port to an output should be equalized to match phases.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power combining circuit mainly used for a microwave circuit.

[0002]

2. Description of the Related Art A conventional coaxial power combining circuit will be described in detail with reference to FIGS.

FIG. 3 shows an example in which a Wilkinson type hybrid circuit is arranged according to the number of composites by using metal conductors 6 arranged on a printed circuit board 8. FIG. 3 shows an example of a four-combining circuit. In each hybrid, the absorption resistor 7 is inserted in the middle of the wiring.

FIG. 4 shows an example of a four-combining circuit using waveguides. This is an example in which three magic T circuits 9 are in-phase synthesized. A terminator (dummy) 10 is attached to each magic T.

[0005]

The first problem is that the conventional Wilkinson-type synthesis circuit has the following problems.
Although the shape can be reduced in size, the use is basically limited by the strip line on the printed circuit board, and it has been difficult to realize a triplate, a rectangular coaxial line, or a circular coaxial line which has lower loss than the strip line. The reason is that a resistor for absorption is required on the circuit surface.

[0006] The second problem is that power durability is inferior, and there is a limit to high output. The reason is that the strip line has a large transmission loss due to a dielectric loss due to its structure, and is not suitable for high power transmission thermally.

A third problem is that the conventional waveguide type synthesis circuit has low loss and excellent power durability, but inevitably increases the size of the device. The reason is that the shape becomes very large because the four ports are spread in all directions.

Therefore, an object of the present invention is to provide a power combining circuit that is small and has little transmission loss.

[0009]

According to the present invention, there is provided a signal processing apparatus comprising: a center conductor formed of a plurality of rat race circuits; a shape similar to the center conductor; And an outer conductor having dimensions such as

[0010]

The power combining circuit according to the present invention has a structure in which a plurality of rat race circuits are combined, and performs a combining operation by phase combining.

[0011]

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows one of the center conductors of a rat race circuit constituting a power combining circuit of the present invention. On a circular ring-shaped center conductor having a length of 1.5 times the wavelength at the used center frequency, four terminals are provided at intervals of 1/4 wavelength.

FIG. 2 (a) shows this rat race circuit
4 shows four combined circuits used. In this power combining circuit, three rat race circuits are combined in phase to form a tournament system.

The rat race circuits 2, 3, and 4 are connected so as to perform in-phase synthesis. Specifically, the combined output from the in-phase input terminals ',' of the rat race circuit 2 is input to the in-phase input terminal of the rat race circuit 3.

On the other hand, the combined output from the in-phase input terminals "," of the rat race circuit 4 is input to the in-phase input terminal of the rat race circuit 3.

In the rat race circuit 3, the combined output ',' input to the in-phase input terminal is output as a combined output.

FIG. 2B shows a diagram in which the center conductor 1 is combined with an outer conductor having a shape similar to that of the center conductor 1 to form a coaxial line. Each of the above-mentioned input / output terminals is structured to be taken out to the outer conductor by a pin.

Next, the operation of one embodiment of the present invention will be described.
This will be described in detail with reference to FIGS.

A rat race circuit, which is a hybrid coupler, is known as a power in-phase combining / distributing circuit, and has a loop shape as shown in FIG.

For example, the input from
And the wave of →→ are combined, but because the respective line lengths have a difference of λg / 2, they cancel each other out of phase and do not output. That is, is considered to be short-circuited.

In the case of, since both the line lengths are λg, they are equally distributed in phase.

The length of the annular portion is 1,5λg, and the impedance is (square root of 2) Z0 (71Ω). Each branch path has Z0 (50Ω).

The power combining circuit according to one embodiment of the present invention has a structure to which this rat race is applied, and its shape is shown in FIG. As an example of configuration, a four-synthesis circuit using three of the present rat race circuits will be taken as an example. In the rat race (A) 2, the input from is distributed equally, and at this time, the signal does not pass because it is a short-circuit port.

Similarly, in the rat races (B) 3 and (C) 4, the input from “is equally distributed to“, ”and the input from“ is equally distributed to “,”. 1 ”, ',',”, ”
It becomes 1/4.

[0025] Here, considering the reverse of the reversibility of the circuit,
Input from ',', "," will be combined and sent to. For example, from each port "1"
Theoretically, there is an output of "4".

In order for the above operation to be satisfied, the output ports ('→,' →,
It is necessary to make the line lengths of “→” and “→” equal to adjust the phase.

When the phase balance is lost due to some influence, a signal is also input to ','.
, ', "Are terminated.

[0028]

A first effect of the present invention is that a simple structure can be realized. The reason that this effect can be obtained is that it is not necessary to directly attach the absorbing resistor on the circuit unlike the Wilkinson type synthesis circuit.

The second effect of the present invention is that, for the same reason as in the first effect, since there is no resistor on the line, not only the strip line type of the printed circuit board but also a triplate, a rectangular coaxial line, a circular It can also be realized with a coaxial substrate or the like, and low loss and improvement in power durability can be achieved. The reason why this effect is obtained is that it is not necessary to directly attach the absorbing resistor on the combining circuit, as in the case of the first effect.

The third effect of the present invention is a reduction in loss.
The reason that this effect can be obtained is that the center conductor is formed by integrally cutting a plurality of rat race circuits, and there is no deterioration in return loss and no increase in loss due to a connection portion or the like.

[Brief description of the drawings]

FIG. 1 is a sectional view of a rat race circuit used in one embodiment of the present invention.

FIG. 2A is a diagram showing a center conductor constituting a four-combination circuit according to one embodiment of the present invention; FIG. 2B is a diagram showing a center conductor constituting a four-combination circuit according to one embodiment of the present invention; FIG. 4 is a top view in which the outer conductor and the conductor are combined.

FIG. 3 is a diagram showing a conventional Wilkinson type 4 synthesis circuit.

FIG. 4 is a diagram showing a conventional waveguide type four combining circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Center conductor 2 Rat race circuit (A) 3 Rat race circuit (B) 4 Rat race circuit (C) 5 Case (outer conductor) 6 Metal conductor part 7 Resistance 8 Printed circuit board (dielectric substrate) 9 Magic T 10 Dummy part

Claims (2)

[Claims] 1. A center conductor composed of a plurality of rat race circuits, and an outer conductor having a shape similar to the center conductor and having a dimension having a desired impedance when combined with the center conductor. A power combining circuit, comprising: 2. The power combining circuit according to claim 1, wherein all the center conductors are integrally cut.