JPH02214207A - Microwave hybrid coupling type amplifier - Google Patents

Abstract

PURPOSE:To reduce the effect of reflection or bypass on each part and to enhance the synthesized efficiency by providing a phase adjustment line between a 3dB hybrid coupler and a reflection type amplifier and providing a matching circuit or a phase adjustment line so as to vary the load reflection coefficient to the output side. CONSTITUTION:Phase adjustment lines 7a,7b whose electric length is variable are inserted between reflection type amplifiers 1a, 1b and a 3dB hybrid coupler 2 and a matching circuit 8 or a phase adjustment line whose electric length is variable is inserted between the 3dB hybrid coupler 2 and an output terminal 6. Thus, the phase and amplitude of power returned to the reflection type amplifiers 1a, 16 are set to a value close to a desired value by adjusting the electric length between the reflection type amplifiers 1a, 1b and the 3dB hybrid coupler 2 and between the 3dB hybrid coupler 2 and the output terminal 6. Thus, stable operation is attained and the synthesis efficiency is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a microwave hybrid coupling amplifier that uses a 3 dB hybrid coupler to combine the outputs of two reflection amplifiers.

[Conventional technology]

FIG. 3 shows, for example, IEET trans,
FIG. 2 is a block diagram of a conventional microwave hybrid coupled amplifier shown in MTT-29 No. 12 (1981), page 1292. In Figure 3, (1n) and (1b) are reflection amplifiers, (2) is a 3dB hybrid coupler, (
3m) and (3b) are the distribution terminals of the 3 dB hybrid coupler, (4) is the input terminal of the 3 dB hybrid coupler, and (5) is the isolation 3 terminal of the 3 dB hybrid coupler.

Reflective amplification! (la) is connected to the distribution terminal (3a), and the reflection type amplifier 1 (lb) is connected to the distribution terminal (3b). In this conventional device, an oscillator is used as the reflection amplifier to operate it as an injection-locked amplifier.

Next, the operation will be explained.

When signal power is input to the input terminal (4), this signal power is transferred to the distribution terminal (
It is equally distributed between 3a) and (3b). At this time, the phase of the signal distributed to the distribution terminal (3b) is the same as that of the distribution terminal (3a).
It is delayed by 90 degrees compared to .

This distributed signal power is reflected in the reflected amplification (IQ) and (
1b), amplified and reflected to the distribution terminal (3a),
Returning to (3b), the 3 d B hybrid coupler (2
) is synthesized by If the phase of the signal returning to the distribution terminal (3b) is delayed by 90° compared to the signal returning to the distribution terminal (3a), the combined signal appears at the isolation terminal (5) and is taken out as an output.

However, if the phase difference between the signal returning to the distribution terminal (3b) and the signal returning to the distribution terminal (3a) is not 90 degrees at this time, a part of the output is transferred to the input terminal (2) of the 3dB hybrid coupler (2).
4), and therefore the synthesis efficiency decreases.

[Problem to be solved by the invention]

In such a conventional microwave hybrid trapezoidal amplifier, each reflection amplifier (la).

When the reflection gain of (1b) is increased, that is, when the input power is made smaller than the reflected and amplified power, each reflection amplifier is Power returned to (1a), (lb), 3dB hybrid coupling! The power input from the input terminal (4) is the power that a part of the output of the reflection amplifier goes around to the other reflection amplifier due to the isolation thin in (2), and the power that returns from the load side to the isolation terminal (5). It becomes a size that cannot be ignored compared to .

Therefore, the signal input to each reflection amplifier (la), (lb) is the reflected power from each distribution terminal (3a), (3b) of the 3 dB hybrid coupler (2), and from one reflection amplifier to the other. First of all, the distribution terminal (
3a).

(3b) The phase difference of the signal that is amplified and returned is 90°
There is a problem that the synthesis efficiency decreases.

Furthermore, the input power may become smaller or larger depending on the phase relationship.

When this input power decreases, the output also decreases accordingly. Furthermore, when used as an injection-locked amplifier, there is a problem that injection locking is no longer applied.

This invention was made to solve the above-mentioned problems, and aims to obtain stable operation and increase synthesis efficiency.

[Means to solve the problem]

The microwave hybrid coupling amplifier according to the present invention includes a phase adjustment line having a variable electrical length inserted between each reflection amplifier and a 3dB hybrid coupler, and a phase adjustment line having a variable electrical length.
A matching circuit or phase adjustment path with variable electrical length is inserted between the dB hybrid coupling domain and the output terminal.

[Effect]

The microwave hybrid coupling amplifier according to the present invention reduces the power returned to each reflection amplifier by adjusting the electrical length between each reflection amplifier and the 3dB hybrid coupler and between the 3dB hybrid coupler and the output terminal. The phase and amplitude can be set to values close to desired values.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (la) and (lb) are reflection amplifiers, (2
) is a 3dB hybrid coupler, (3!l), (3b)
is the distribution terminal of 3dB hybrid coupling (2), (4)
is the input terminal of the 3dB hybrid coupling N(2), (5)
is the isolation terminal of the 3 dB hybrid coupler (2), (6) is the output terminal of the microwave hybrid coupling amplifier, and (7a) and (7b) are the isolation terminals of the above-mentioned reflection amplifier (1).
a), (lb) and the above distribution terminal (3a).

(3b) and the phase adjustment lines s, (
8) is a sticky circuit inserted between the isolation terminal (5) and the output terminal (6).

In the microwave hybrid coupling type amplifier configured in this way, the above-mentioned reflection type amplifier (la) is included.

(lb), 3dB hybrid coupler (2), phase F
If the reflection loss and transmission loss of the J straightening line (7) and the matching circuit (8) and their phases are determined as follows, each value is expressed by the first equation ~
The relationship of equation 5 is expressed as WI4.

LL, θ, 1 3 dB Hybrid coupler reflection loss and its phase L2・θHz ' 3 d B tz Hybrid coupler's coupling amount and its phase L3. θ,..., Isolation of 3dB hybrid coupler and its phase L, θ: Reflection loss expected from the isolation terminal to the output side and its phase θ11 =θ, 2 Each phase adjustment line length θ#1. θoz Reflection phase θ1 of each reflection amplifier. +
205. -θ, 2+2012 (1) θ0. +2
0n+θH, = 360°・n (2) θo2+2θ1
□+θM, = 360°・rn (3) (n, m are integers including O) L3-L no
(4) θN3-2θ9□10θ7-90°+360°-
n (5) Next, the operation will be explained. Since the process of amplifying the input signal is almost the same as the conventional one, only the effects of reflection of the 3 dB hybrid coupler, isolation, and reflection of the load will be described below.

When the first equation is satisfied, each reflection type amplification! (la).

The input voltages V+ and V2 to (1b) are given by Equations 6 and 7, if the influence of multiple reflections is ignored.

−2a]ζ1−″tsu (6) V, = , ,;
θ・−f51; 1 princess′″0・+2 zoPet%t, e−”
) ('7) where θI=θ1. +2011+θM+ θ2=θ, I+2θrt+θs3+90°θ3=θ61
+2θH + 2θH Otsu θlPI: Input power Po2 Output power of reflection amplifier Equations 6 and 7, the first term is the power of the input signal, and the second term is the power amplified by the reflection amplifier at the 3 dB hybrid coupler. The reflected power, the third term is the power when the output power of each reflection amplifier is combined by the 3 dB hybrid coupler isolation circuit, and the fourth term is the power reflected by the matching circuit and load out of the combined output power. are shown respectively.

As mentioned above, Equations 6 and 7 show that when the gain of the reflection amplifier is increased and Pi is reduced, the second terms to
Since the fourth term becomes a value that cannot be ignored, el ~
This shows that vI, 2 becomes small depending on the phase of e3, and phase synchronization is no longer applied. Matco, 6th
Since the third and fourth terms exist in Equations and Equations 7, the phase difference of the reflected waves to the distribution terminals (3a) and (3b) deviates from 90', indicating that the synthesis efficiency decreases. .

First, conditions for increasing synthesis efficiency will be explained.

To increase the synthesis efficiency, connect the distribution terminal (
3a), (3b) The amplitudes of the voltages v, , v2 reflected to 3a) and 3b may be made the same, and the phases may be shifted by 90°.

Note that the signs of the third and fourth terms in the sixth and seventh equations are different and the coefficients are equal, and by substituting 12=0°5, the following condition is obtained.

Suspension e-4=Roe゛bow, that is L3=Lz (4)θ□
, =2θH2+θt-90°+360°a7L (5
) This means that the power due to the isolation (L3) of the 3 dB hybrid coupler cancels out the power due to the reflection (L, ) on the matching circuit side.

Next, conditions for stable operation of the microwave hybrid-rad coupled amplifier will be explained.

In order for injection locking to operate stably with low input power, it is desirable to maximize the input voltages V,,V,. The conditions for satisfying the fourth equation and maximizing V, , V2 are the first term and the second term.
By making the terms in phase, the equation θ, −〇 is obtained, and the following equation is obtained.

θ0. +201. +θH, = 360°・n (
2) θ62 +2θ, 2+θ%, = 360°・rn
(3) The second and third equations mean that the phase of the reflected wave at the 3 dB hybrid coupler and the phase of the input signal are made to be in phase.

Therefore, the electrical lengths of the respective phase adjustment lines inserted between the 3 dB hybrid coupler and the first and second reflection type amplification amplifiers and the t co-matching circuit inserted between the isolation terminal and the output terminal are By setting as described above, the synthesis efficiency is increased and the microwave hybrid coupling type amplification tube operates stably.

In the above embodiment, the isolation terminal (5) and the output terminal (6
), but the present invention is not limited to this, and the present invention is not limited to this, but also cancels the power returned from the load side and the power that goes around to the reflection amplifier by the isolation blind of the 3 dB hybrid coupling gain. Any method that suits you is fine.

FIG. 2 is a diagram showing another embodiment, in which the phase adjustment line (7) is connected between the isolation terminal (5) and the output terminal (6).
c), and one isolator (9), for example, is connected to the output terminal (6). 3dB hybrid coupler (
2) isolation.

If the reflection loss Lxsa of the isolator (9) is approximately equal to the reflection loss Lxsa of the isolator (9), the eighth equation is satisfied.

L H” Lxza = Lx (8)
Further, the electrical length θ of the phase adjustment line (7C) is set so as to satisfy Equation 9.

θ□, =2θH2〇1-90°+360'-n
(9) Also, in the above description, an in-shell reflection amplifier will be described as each reflection amplifier, but an injection-locked amplifier may also be used, and the same effects as in the above embodiments can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, a phase adjustment line is provided between the 3dB hybrid coupler and the reflection amplifier, and a matching circuit or phase adjustment line is provided on the output side so as to change the reflection coefficient of the load. By providing this structure, it is possible to reduce the effects of reflections and wrap-arounds in various parts, thereby increasing the synthesis efficiency and, in the case of an injection-locked amplifier, achieving stable operation.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a microwave hybrid coupling type amplifier showing one embodiment of the present invention, Fig. 2 is a block diagram showing another embodiment of the invention, and Fig. 3 is a block diagram of a conventional microwave hybrid coupling type amplifier. FIG. In the figure, symbols (la) and (lb) are reflection amplifiers, (2) is a 3 dB hybrid coupler, and (3a). (3b) is the distribution terminal, (4) is the input terminal, (5) is the isolation terminal, (6) is the output terminal, (7a)
7b) and (70) are phase adjustment lines, and (8) is a matching circuit. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. 1st vA. 2nd rIJ.

Claims (1)

[Claims] A first reflection amplifier is connected to a first distribution terminal of the 3dB hybrid coupler, a second reflection amplifier is connected to a second distribution terminal, and the input terminal of the 3dB hybrid coupler is connected to a microwave hybrid coupling type. In a microwave hybrid coupling amplifier in which the input terminal of the amplifier and the isolation terminal of the 3 dB hybrid coupler are the output terminals of the microwave hybrid coupling amplifier, the first and second distribution terminals of the 3 dB hybrid coupler and , characterized in that a phase adjustment line with a variable electrical length is inserted between the first and second reflection amplifiers, and a phase adjustment line with a variable electrical length or a matching circuit is added to the output terminal. Microwave hybrid coupled amplifier