JP2001284995A - Microwave pulse power amplifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microwave pulse power amplifier capable of making the rise or fall of a microwave pulse sufficiently smooth. SOLUTION: Concerning the microwave pulse power amplifier, with which a first amplifier circuit 11 and a final amplifier circuit 12 for amplifying the microwave pulse are connected on plural stages, operation time for amplifying an inputted microwave pulse P1 is extended for the first amplifier circuit 11 connected on the pre-stage rather than the final amplifier circuit 12 connected on the post-stage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave pulse power amplifier capable of suppressing the spread of the frequency spectrum of a microwave pulse when amplifying the microwave pulse used in a phased array radar or the like.

[0002]

2. Description of the Related Art In a phased array radar or the like, a microwave pulse is used as a transmission signal. In the case of using such a pulse-modulated microwave, it is necessary to reduce the spread of the frequency spectrum and narrow the occupied frequency bandwidth in order to suppress interference with other devices. One method of narrowing the occupied frequency bandwidth is, for example, a method of gradualizing the envelope waveform of the rising and falling edges of the microwave pulse.

Here, a conventional microwave pulse power amplifier for making the envelope waveform of a microwave pulse gentle will be described with reference to FIG.

[0004] The reference symbol IN denotes an input terminal.
For example, 2 of the first-stage amplifier circuit 41 and the last-stage amplifier circuit 42
A stage amplifier circuit is connected. The output terminal OUT is connected to the last-stage amplifier circuit 42. The first-stage amplifier circuit 41 and the last-stage amplifier circuit 42 are configured by a field effect transistor, a bipolar transistor, or the like, and are configured to perform, for example, a class A operation or an AB class operation.

Reference numeral 43 denotes a bias power supply. The power supply voltage supplied from the bias power supply 43 is shaped into a trapezoidal waveform by a waveform shaping circuit 44, and the bias voltage B1 is applied to the first-stage amplifier 41 and the last-stage amplifier 42, respectively. , B2. First stage amplifier circuit 41 and final stage amplifier circuit 4
No. 2 enters an operation state when the bias voltages B1 and B2 are applied, and enters a non-operation state when the bias voltages B1 and B2 are not applied.

In the above configuration, a microwave pulse P1 as shown in FIG. 5 (a) is input from an input terminal IN, and is sequentially amplified by a first-stage amplifier circuit 41 and a last-stage amplifier circuit 42. It is output as a microwave pulse P2 as shown in FIG.

At this time, the first stage amplifier circuit 41 and the last stage amplifier circuit 42 are supplied from the waveform shaping circuit 44 with the configuration shown in FIG.
Bias voltages B1 and B2 as shown in (c) are applied. The bias voltages B1 and B2 gradually rise after the input of the microwave pulse P1, and gradually fall before the input of the microwave pulse P1 is cut off.

Therefore, the output terminal OUT is connected to FIG.
As shown in (d), the rising and falling envelope waveforms gradually change in accordance with the changes in the bias voltages B1 and B2, and the microwave pulse P2 in which the spread of the frequency spectrum is suppressed is output.

[0009]

In a conventional microwave pulse amplifier, when an amplifier circuit is connected to a plurality of stages,
The timing of the rise and fall of the bias voltage applied to each amplifier circuit is the same. In addition, in such a configuration, if the rising and falling of the bias voltage supplied to the amplifier circuit is made gentle, the waveform of the bias voltage collapses from an ideal trapezoidal shape, and the slope of the rising and falling becomes gentle. However, there is a problem that the delay time increases. Therefore, there is a disadvantage that the rising and falling of the output microwave pulse does not have a sufficiently gentle slope.

An object of the present invention is to solve the above-mentioned disadvantages, and an object of the present invention is to provide a microwave pulse amplifier which can make the rising and falling of the microwave pulse sufficiently gentle.

[0011]

SUMMARY OF THE INVENTION The present invention relates to a microwave pulse power amplifier in which an amplifier circuit for amplifying a microwave pulse is connected in a plurality of stages, wherein at least one amplifier circuit connected in a preceding stage is connected to a subsequent stage. Is characterized in that the operation time for amplifying the microwave pulse is longer than at least one amplifier circuit connected to.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. Symbol IN indicates an input terminal, and input terminal I
N is connected to, for example, a two-stage amplifier circuit of a first-stage amplifier circuit 11 and a last-stage amplifier circuit 12. Final stage amplifier 1
2 is connected to an output terminal OUT. First stage amplifier 1
The first and last-stage amplifier circuits 12 are composed of a field effect transistor, a bipolar transistor, or the like, and are configured to perform, for example, a class A operation or an AB class operation.

Reference numeral 13 denotes a bias power supply, and a power supply voltage supplied from the bias power supply 13 includes two waveform shaping circuits 1.
Waveforms are shaped into trapezoids at 41 and 142, respectively, and predetermined bias voltages B1 and B2 are generated. Waveform shaping circuit 1
The bias voltage B1 generated in the first stage 41
And the bias voltage B2 generated by the waveform shaping circuit 142 is applied to the final-stage amplifier circuit 12.

The first-stage amplifier circuit 11 and the last-stage amplifier circuit 12
Usually, it is configured using a semiconductor element such as a field effect transistor or a bipolar transistor. In this case, the bias voltage B generated by the waveform shaping circuits 141 and 142
1, B2 is applied to the gate or drain electrode in the case of a field effect transistor, and is configured to temporally control the base or collector current in the case of a bipolar transistor.

Note that, when the bias voltages B1 and B2 are applied, the first-stage amplifier circuit 11 and the last-stage amplifier circuit 12 enter an operation state of amplifying an input signal, and the bias voltages B1 and
If B2 is not applied, it is assumed to be in a non-operation state.

In the above configuration, a microwave pulse P1 as shown in FIG. 2A is inputted from the input terminal IN, and is sequentially amplified by the first-stage amplifier circuit 11 and the last-stage amplifier circuit 12, and as shown in FIG. The amplified microwave pulse P2 as shown is output to the output terminal OUT.

At this time, the first stage amplifier circuit 11
As shown in (b), a bias voltage B1 that rises slowly after the input of the microwave pulse P1 and gradually falls before the input of the microwave pulse P1 is cut off is applied. In addition, the final-stage amplifier circuit 12 has the configuration shown in FIG.
As shown in FIG. 7, a bias voltage B2 that gradually rises later than the bias voltage B1 and gradually falls earlier than the bias voltage B1 is applied.

As described above, the first-stage amplifier circuit 11 includes:
A bias voltage B1 that gradually rises after the input of the microwave pulse P1 is applied. Therefore, the rising edge of the envelope of the microwave pulse amplified by the first-stage amplifier circuit 11 is gently shaped like the waveform of the bias voltage B1 and is input to the last-stage amplifier circuit 12. At this time, the bias voltage B2 is not applied to the final-stage amplifier circuit 12. Therefore, in the non-operating state, the final-stage amplifier circuit 12 attenuates by the isolation of several tens of dB and outputs the rising portion of the microwave pulse P2.

Thereafter, the first-stage amplifier circuit 11 enters an operating state, and after the microwave pulse output from the first-stage amplifier circuit 11 rises, the bias voltage B2 applied to the last-stage amplifier circuit 12 rises slowly. Therefore, the microwave pulse P2 output from the last-stage amplifier circuit 12
Rises after the output of the first-stage amplifier circuit 11 attenuated by the isolation of the last-stage amplifier circuit 12. For this reason, the rising time of the microwave pulse P2 output from the last-stage amplifier circuit 12 depends on the bias voltage B1 applied to the first-stage amplifier circuit 11 and the last-stage amplifier circuit 12,
This is the time obtained by adding the rise time of B2.

On the other hand, at the falling edge of the microwave pulse, while the microwave pulse P1 is input, FIG.
As shown in (c), the bias voltage B2 of the final-stage amplifier circuit 12 gradually falls. Thereafter, as shown in FIG. 2B, the bias voltage B1 of the first-stage amplifier circuit 11 gradually falls. Therefore, when the bias voltage B1 of the first-stage amplifier circuit 11 falls, the last-stage amplifier circuit 12 is not operating. For this reason, the microwave pulse P2 is output after being attenuated by the amount of the isolation, and the fall time is also the time obtained by adding the fall times of the bias voltages B1 and B2 applied to the first-stage amplifier circuit 11 and the last-stage amplifier circuit 12. become.

According to the above configuration, the rise and fall times of the envelope of the output microwave pulse are
This time is the sum of the rise and fall times of each of the amplifier circuits connected in a plurality of stages. For this reason, the rise and fall can be made gentler than in the case where the rise and fall of each amplifier circuit are shaped at the same timing. As a result, the spread of the frequency spectrum is suppressed, and the occupied frequency band is narrowed.

According to the present invention, the rising and falling timings of the pulsed bias voltage for each amplifying stage are set to two times.
The rise is delayed and the fall is accelerated in a later stage farther than the former stage closer to the input side. In this method, the rise and fall times of the entire amplifier are values obtained by adding the rise and fall times of the respective amplification stages. Therefore, the inclined portion of the microwave pulse can be easily made gentle, and the delay time does not increase.

In the case of a class A or class AB semiconductor device, a switch circuit is usually used in combination to apply a bias voltage or stop applying a bias voltage. In the present invention, since the rising and falling times of the respective amplification stages are made gradual and the times are shifted, no special circuit such as a PIN diode modulator for directly pulse-modulating the microwave is required. Therefore, the overall circuit configuration is reduced in size and cost.

Next, another embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. FIG. 3 shows a case in which the amplifier circuit is configured in three stages. Parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and overlapping description is partially omitted.

In this embodiment, a second-stage amplifier circuit 31 is connected between the first-stage amplifier circuit 11 and the last-stage amplifier circuit 12. Then, the bias voltage B1 generated by the waveform shaping circuit 141 is commonly applied to the first-stage amplifier circuit 11 and the second-stage amplifier circuit 31.

In the above configuration, when the input microwave pulse P1 (FIG. 2) rises, the bias voltage B1 applied to the first-stage amplifier circuit 11 and the second-stage amplifier circuit 31 near the input side is moderate and Stand up at the same time. Thereafter, the bias voltage B2 applied to the final-stage amplifier circuit 12 gradually rises.

On the other hand, when the microwave pulse P1 (FIG. 2) falls, the bias voltage B1
Then, the bias voltage B2 of the first-stage amplifier circuit 11 and the second-stage amplifier circuit 31 falls. In this case, the same effect as in FIG. 1 can be obtained.

In each of the above-described embodiments, of the amplifier circuits connected in a plurality of stages, at least one amplifier circuit connected near the input side and at least one amplifier circuit connected farther than the input circuit are connected. The bias voltage applied to the circuit is shifted in time both at the rise and at the fall. However, it is also possible to adopt a configuration in which the time is shifted only for one of the rise and the fall.

In each of the above embodiments, the case where the number of connected amplifier circuits is two or three is described. However, the number of connected amplifier circuits can be four or more.

[0030]

According to the present invention, a microwave pulse amplifier that makes the rising and falling of the microwave pulse gentle can be realized.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram for explaining an embodiment of the present invention.

FIG. 2 is a waveform chart for explaining an embodiment of the present invention.

FIG. 3 is a circuit configuration diagram for explaining another embodiment of the present invention.

FIG. 4 is a circuit configuration diagram for explaining a conventional example.

FIG. 5 is a waveform chart for explaining a conventional example.

[Explanation of symbols]

 Reference Signs List 11 initial stage amplifier circuit 12 final stage amplifier circuit 13 bias power supply 141, 142 waveform shaping circuit P1 input microwave pulse P2 output microwave pulse B1 bias voltage applied to first stage amplifier circuit B2 final stage Bias voltage applied to amplifier circuit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5J069 AA01 AA41 AA54 AC03 AC04 CA27 CA48 CA49 FA10 FA18 HA40 KA12 KA25 KA49 MA08 SA14 TA01 TA06 5J092 AA01 AA41 AA54 CA27 CA48 CA49 FA10 FA18 FR10 FR14 HA40 KA12 TA25 MA06

Claims (4)

[Claims] 1. A microwave pulse power amplifier in which amplification circuits for amplifying microwave pulses are connected in a plurality of stages, wherein at least one amplification circuit connected to a preceding stage is connected to at least one amplification circuit connected to a subsequent stage. The microwave pulse power characterized in that the operation time for amplifying the microwave pulse is longer than that of the circuit, and the operation time for amplifying the microwave pulse in each stage is shorter than the pulse width of the input microwave pulse. amplifier. 2. A microwave pulse power amplifier in which an amplification circuit for amplifying a microwave pulse is connected in a plurality of stages, wherein at least one amplification circuit connected in a preceding stage is connected to at least one amplification circuit connected in a subsequent stage. The microwave pulse characterized in that the operation of amplifying the microwave pulse starts earlier than the circuit and the operation time of amplifying the microwave pulse in each stage is shorter than the pulse width of the inputted microwave pulse. Power amplifier. 3. A microwave pulse power amplifier in which amplification circuits for amplifying microwave pulses are connected in a plurality of stages, wherein at least one amplification circuit connected in a preceding stage is connected to at least one amplification circuit connected in a subsequent stage. The microwave pulse characterized in that the operation of amplifying the microwave pulse ends later than the circuit, and the operation time for amplifying the microwave pulse in each stage is shorter than the pulse width of the input microwave pulse. Power amplifier. 4. A microwave pulse power amplifier in which amplification circuits for amplifying microwave pulses are connected in a plurality of stages, wherein at least one amplification circuit connected in a preceding stage is connected to at least one amplification circuit connected in a subsequent stage. The operation of amplifying the microwave pulse starts earlier and ends later than the circuit, and the operation time of amplifying the microwave pulse in each stage is shorter than the pulse width of the inputted microwave pulse. Microwave pulse power amplifier.