JPH02305203A - Microwave amplifier circuit - Google Patents

Abstract

PURPOSE:To constitute an amplifier circuit with high efficiency and low power consumption by dividing the power of an inputted microwave signal into two, inverting the phase and amplifying the signal based on the principle of push-pull amplification. CONSTITUTION:Power of a microwave signal S1 inputted from an input terminal 21 is divided into two with an input power divider 2 and the phase is shifted with Schiffman phase shifters 3a, 4a so that the relative phase of output signals S4, S5 is 180 deg.. Then the resulting signal is fed respectively to the amplifiers 5, 6, where class AB2 amplification is applied. Output signals S6, S7 of the amplifiers 5, 6 are fed respectively to band pass filters 7a, 8a, filtered and an even-order harmonic is cancelled, the relative phase difference of output signals S10, S11 is taken as 0 deg. with Schiffman phase shifters 9a, 10a, the signals are synthesized and the result is outputted from an output terminal 22.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a microwave amplification circuit for amplifying microwave signals.

[Conventional technology]

A conventional microwave amplifier circuit is shown in FIG.

The microwave amplifier circuit 50 shown in the figure is a circuit using a balanced power combining circuit composed of a hybrid coupler 51, 52 and an amplifier 53, 54. According to the amplifier circuit 50, the microwave signal input to the input terminal 55 is divided by the hybrid coupler 51 in the previous stage with a phase relationship of 90°, and each output signal of the coupler 51 is divided by the amplifiers 53 and 54. amplified and amplified micro~
The 2-wave signal is combined by a hybrid coupler 52 at the subsequent stage.

[Problem to be solved by the invention]

By the way, since the amplifiers 53 and 54 in the conventional microwave amplification circuit 50 described above must operate in class A,
In the end, class-A operation has drawbacks such as low gain, inability to obtain large output, high power consumption, and poor efficiency.

It is an object of the present invention to provide a microwave amplification circuit which eliminates the problems existing in the conventional technology.

[Means to solve the problem]

The microwave amplifier circuit 1 according to the present invention includes an input power divider 2 that divides the power of an input microwave signal Sl into two, and each output signal S in the input power divider 2.
2. A pair of input-side phase shifters 3.4 that shift the phase so that the relative phase difference is 180° (inversion) with respect to S3.
a pair of amplifiers 5.6 that amplify the output signals S4 and S5 of the phase inversion unit H, and a pair of filters 7 that filter the output signals S6 and S7 of the amplifier 5.6. .8 and each output signal S8 of this filter 7.8
, a pair of output side phase shifters 9 and IO that shift the phase so that the relative phase difference is 0° (in phase) with respect to S9,
Each output signal 5IO of this output side phase shifter 9.10
It is characterized by comprising an output-side power divider II that combines 1Sll.

[For production]

According to the microwave amplifier circuit I according to the present invention, the power of the input microwave signal S1 is divided into two by the input side power divider 2, and further by the input side phase shifter 3.4.
The respective phases are shifted so that the relative phase difference becomes 180°. That is, the phase is inverted by the phase inverter H.

The output signals S4 and S5 whose phases have been inverted by the intermediate section H are each amplified by an amplifier 5.6 based on AB2 class operation, for example, and are further passed through a filter 7.8 and filtered. Since the filter 7.8 grounds the ends of the transmission line on its primary and secondary sides, the lumped constant circuit (equivalent circuit) shown in Fig. 3 is used.
This is the same as the state in which the midpoint 30a of 30 is grounded. in the end,
Since the even harmonics flow to the source side of the amplifier 5.6,
The effect is the same as when the midpoint of a transformer used in a push-pull circuit is grounded.

Then, each output signal S8, S9 of the filter 7.8 has a relative phase difference of 0° by the output side phase shifter 9.10.
The phase is shifted so that the output signal 5IO
1Sll is combined by the output side power divider 11.

Therefore, the amplified microwave signal S12 is output from the power divider 12.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail based on the drawings.

First, the configuration of the microwave amplifier circuit 1 will be explained with reference to FIG.

Reference numeral 2 denotes an input-side □ power divider, which includes an input terminal 21 for the microwave signal S1 to be amplified. In addition, one output terminal of the power divider 2 has an input side phase shifter 3.
A λ/2 Schiffman phase shifter 3 using a microstrip line forming the input side phase shifter 4 is connected to the other output terminal, and a λ/4 Schiffman phase shifter 4a using a microstrip line forming the input side phase shifter 4 is connected to the other output terminal. . The phase inverter H is configured as described above.

Further, an amplifier 5.6 having the same performance is connected to the output side of each phase shifter 3a, 4a, and this amplifier 5.6 is operated in class AB2. The output side of each amplifier 5.6 is connected to the primary side of bandpass filters 7a and 8a formed by microstrip lines constituting a filter 7.8, respectively. The filters 7a and 8a respectively ground the terminal ends of the transmission lines on the primary and secondary sides thereof.

In this case, the center frequency and bandwidth of the bandpass filters 7'a, 8a are determined by the shape of the microstrip line.

On the other hand, on the secondary side of the bandpass filter 7a in a system using a λ/2 Schiffman phase shifter on the input side, a λ/4 Schiffman phase shifter 9a formed by a microstrip line constituting the output side phase shifter 9 is connected. In addition, on the secondary side of the bandpass filter 8a in a system using a λ/4 Schiffman phase shifter on the input side, there is a λ/2 Schiffman phase shifter 10a using a microslip line that constitutes the output side phase shifter IO. Connect.

The output side of each Schiffman phase shifter 9XL, 10λ is connected to an output side power divider 11 for signal synthesis. Note that 22 is the output terminal of the output side power divider 11, that is, the output terminal of the present amplifier circuit 1.

Next, the functions of the microwave amplifier circuit 1 will be explained.

First, the power of the microwave signal Sl input from the input terminal 2I is divided into two by the input side power divider 2.

Then, one output signal S2 of the input side power divider 2
is supplied to the λ/2 Schiffman phase shifter 3a and delayed by one wavelength. Further, the other output signal S3 of the input side power divider 2 is supplied to the λ/4 Schiffman phase shifter 4a and delayed by 1/2 wavelength. As a result, as shown in FIG. 2, the relative phases of the output signals S4 and S5 of the Schiffman phase shifters 3a and 4a are shifted by 180 degrees. In this way, a pair of Schiffman phase shifters 3a
and 4a have a phase inversion function.

The respective output signals S4, S5 of the Schiffman phase shifters 3a, 4a are then supplied to amplifiers 5.6, respectively, and A
Amplification is performed using class 82 operation.

Each output signal S6, S7 of the amplifier 5.6 is supplied to a bandpass filter 7a, 8a, respectively, where it is filtered and even harmonics are canceled.

Then, the output signal S8 of one bandpass filter 7a
is supplied to the λ/4 Schiffman phase shifter 9a, and
Delayed by two wavelengths. As a result, the input microwave signal S1 is delayed by 3/2 wavelength. The output signal S9 of the other bandpass filter 8a is supplied to a λ/2 Schiffman phase shifter 10 and is delayed by one wavelength. As a result, for the manually generated microwave signal S1, 372
There will be a delay by the wavelength, so the Schiffman phase shifter 9
The relative phase difference between the output signals 5IO1Sll of a and IOa is Oo. And Schiffman phase shifter 9a, 1
Each output signal 5lO1Sll of 0a is supplied to the output side power divider 11, and the combined microwave signal S12 is outputted from the output terminal 22.

In another embodiment, a bandpass filter 32.33 similar to the bandpass filters 7a, 8a may be inserted and connected in front of the amplifier 5.6, as shown in FIG. This has the advantage of facilitating impedance matching.

Although the embodiments have been described in detail above, the present invention is not limited to these embodiments.

For example, the amount of phase shift of each phase shifter is arbitrary,
As a result, the relative phase difference of the input signal to the amplifier is 180
It is good if the relative phase difference of the final output signal of the microwave amplifier circuit becomes 0° as the angle becomes 0°. Therefore, the number of phase shifters is arbitrary. Further, the operation of the amplifier may be in other operation modes such as AB, class, etc. In addition, the detailed circuit configuration, parts, etc. may be arbitrarily changed without departing from the gist of the present invention.

〔Effect of the invention〕

As described above, the microwave amplifier circuit according to the present invention amplifies the input microwave signal based on the push-pull amplification principle by dividing the power of the input microwave signal into two and inverting the phase. Therefore, the amplifier used has class A operation. This eliminates the need for a large gain, provides a large output, and has the remarkable effect of configuring an efficient amplifier circuit with low consumption.

[Brief explanation of drawings]

Figure 1: A circuit diagram of the microwave amplifier circuit according to the present invention; Figure 2: Time chart of signal waveforms in the amplifier circuit; Figure 3: An equivalent circuit diagram showing a part of the amplifier circuit; Figure 4: Two diagrams. A circuit diagram of a microwave amplifier circuit according to another embodiment of the invention. FIG. 5: A circuit diagram of a microwave amplifier circuit according to a conventional technique. In the drawing, microwave amplifier circuit 2: input side power divider 3.4 two-power side phase lid 5.6 amplifier 7, 8: filter 9.10: output side phase shifter 11, output side power divider SL, 312 micro wave signal S2. S3. S4. S5. S6. S7. S8゜S9. S
IO, S11. : Output signal H: Phase inversion section

Claims (1)

[Claims] [1] An input-side power divider that divides the power of an input microwave signal into two, and a phase shift for each output signal in the input-side power divider so that the relative phase difference is 180°. a phase inverter having a pair of input-side phase shifters; a pair of amplifiers for amplifying each output signal of the phase inverter; a pair of filters for filtering each output signal of the amplifier; a pair of output-side phase shifters that shift the phase so that the relative phase difference becomes 0°; and an output-side power divider that combines the output signals of the output-side phase shifters. wave amplification circuit. [2] The microwave amplification circuit according to claim 1, wherein the phase shifter is a Schiffman phase shifter. [3] The microwave amplification circuit according to claim 1, wherein the filter is a bandpass filter. [4] The microwave amplification circuit according to claim 1, further comprising a filter inserted and connected in front of the amplifier.