JPS63136704A - Microwave amplifier gain stabilizing circuit - Google Patents

Abstract

PURPOSE:To simply execute the compensation for the frequency and temperature by using a ROM for a gain setting section applying the gain of a variable attenuator through an attenuator control section and allowing the ROM to store the gain correction quantity to the information such as temperature or frequency and using its contents so as to stabilize the gain. CONSTITUTION:An inputting microwave is amplified by the gain depending on an amplifier 3 and a variable attenuator 2 and goes to an output port. When the frequency band to be amplified is widen in this case, the gain of the microwave circuit section is not constant over the entire region but has a deviation. The set channel is given from a frequency setting section 15 to a gain setting section 13 and the correction quantity included in the gain setting section 13 with respect to each frequency stored in advance in the ROM 14 is given to an attenuator control section 4 to adjust the gain of the variable attenuator thereby facilitating the correction of the deviation of the frequency of the microwave circuit section and stabilizing the gain.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a circuit for stabilizing the gain of a microwave amplifier.

[Conventional technology]

FIG. 2 is a configuration diagram showing a conventional gain stabilization circuit presented, for example, at the 1986 IEICE General Conference (828). In the figure, 1 is a microwave circuit section, and this circuit includes a variable attenuator 2. An amplifier 3 is included, to which an isolator 6, a bandpass filter 72, a local oscillator 83 and a frequency converter 9 are connected. Further, a temperature sensor 10 having an attenuator control section 4 and a temperature detection section 5 is connected to the variable attenuator 2.

Next, the operation will be explained. In Fig. 2, the intermediate frequency signal (IF multiplied signal is sent to the amplifier 3,
It passes through a variable attenuator 2, a local oscillator 8 and a frequency converter 9.
After the signal is converted into an RF frequency multiplied signal, it passes through an isolator 6, a bandpass filter 7, and an amplifier 3, and is output from an output port. Here, the variable attenuator 2 is provided to adjust the amplification degree (gain) of the signal between the input port and the output port. In this figure, a temperature sensor 10 is connected to the variable attenuator 2, and the variable attenuator 2 is connected to the attenuator control section 4 using temperature information from the output of the temperature detection section 5 to measure the variation in gain due to temperature.
It is corrected by adjusting using .

In addition, as shown in FIG. 3, as another conventional technique, a part of the input and a part of the output are taken out by a coupler 11, the two are compared by a comparison circuit 12, and the difference is made constant. AGC (
There is also an 8 auto Galn Control) circuit.

[Problem that the invention seeks to solve]

Since the conventional gain stabilizing circuit is configured as described above, it is difficult to correct frequency fluctuations in the gain, and it is also difficult to adjust when the rate of change due to temperature differs depending on each microwave amplifier.

Further, an AGC circuit is available as a solution to the above problem, but this also has the disadvantage of being an expensive circuit.

This invention was made to solve the above-mentioned problems, and can compensate not only for fluctuations due to one temperature but also for frequency fluctuations, gain setting, and compensation for variations in microwave amplifiers. It is an object of the present invention to provide a microwave amplifier gain stabilizing circuit that is easy to adjust and is inexpensive.

[Means for solving problems]

The microwave amplifier gain stabilization circuit according to the present invention uses a ROM in the gain setting section that sets the gain of the variable attenuator through the attenuator control section, and stores gain correction amounts for required information such as temperature or frequency in the ROM. The content is used to stabilize the gain.

[Effect]

In the gain stabilizing circuit according to the present invention, since the amount of compensation for eliminating the gain deviation of the microwave amplifier is stored in the ROM, the amount of compensation for eliminating the gain deviation of the microwave amplifier is stored in the ROM.
The variable attenuator can be adjusted through the attenuator control section by the gain setting section including the attenuator control section, and the gain can be stabilized.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure shows a microwave amplifier gain stabilization circuit according to an embodiment of the present invention. In the figure, 13 is a gain setting section, which includes a ROM 14 therein. Further, 15 is a frequency setting section.

Next, the operation will be explained. In FIG. 1, the input microwave is amplified with a gain determined by an amplifier 3 and a variable attenuator 2, and is directed to an output port. At this time, when the frequency band to be amplified is wide, the gain of the microwave circuit section is not constant but has deviation within the band. Furthermore, in actual amplifier operation, a method is often used in which the band used is further divided into subdivided channels and information is sent within each channel band.

Therefore, in this embodiment, the setting channel set in this way is transmitted from the frequency setting section 15 to the gain setting section 13, and the correction amount for each frequency stored in advance in the ROM 14 included in this gain setting section 13 is attenuated. The gain of the variable attenuator 2 is adjusted by transmitting the signal to the microwave circuit section 4, thereby making it possible to easily correct the frequency deviation of the microwave circuit section 1 and stabilize the gain.

Figure 4 is a schematic diagram showing this situation. As shown in Figure 4 fat, the gain characteristic of variable attenuator 2, which has a gain deviation of 2.5 dB, is compensated by the correction attenuation amount shown in Figure 4 fb). By performing the correction, the gain deviation can be reduced to about 1.5 dB as shown in FIG. 4 (C1).

Further, in this correction method, by changing the correction amount in the ROM based on the characteristics specific to each microwave amplifier, it is possible to easily compensate for variations in each microwave amplifier. In addition, since the detection circuit and comparison circuit required for the 〇〇 circuit are not required, the device can be realized at low cost.

In the above embodiment, the gain correction was performed using the frequency information from the frequency setting section 15, but there is also a method in which a temperature detection section 5 is provided as shown in FIG. 5, and the gain correction is performed using the temperature information. Furthermore, as shown in FIG. 6, a gain indicating section 16 for indicating the gain of the variable attenuator 2 may be provided to change the absolute amount of gain. Further, the combination of frequency compensation and temperature compensation shown in FIG. 7, the combination of frequency compensation, temperature compensation, and absolute amount change in gain shown in FIG. 8, the combination of frequency compensation and absolute amount change in gain shown in FIG. 9, It is also possible to implement a combination of temperature compensation and absolute change in gain as shown in FIG.

Incidentally, in the above embodiment, a method of performing frequency compensation using the frequency of each channel has been described, but this can be implemented by other methods as long as frequency information can be provided by some means.

〔Effect of the invention〕

As described above, according to the present invention, a gain setting section including a ROM is used to set a variable attenuator, so that a microwave amplifier gain stabilization circuit that can easily and inexpensively compensate for frequency and temperature is provided. There are benefits to be gained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a microwave amplifier stabilizing circuit according to an embodiment of the present invention, FIGS. 2 and 3 are block diagrams showing a conventional example, and FIG. 4 is for explaining the operation of the device of the above embodiment. The characteristic diagrams of FIGS. 5 to 10 are configuration diagrams showing other embodiments of the present invention. 1 is a microwave circuit section, 2 is a variable attenuator, 3 is an amplifier,
4 is an attenuator control section, 5 is a temperature detector, 6 is an isolator, 7 is a bandpass filter, 8 is a local oscillator, 9 is a frequency converter, 10 is a temperature sensor, 11 is a coupler, 12 is a comparison circuit , 13 is a gain setting section, 14 is a ROM, 15 is a frequency setting section, and 16 is a gain instruction section. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (8)

[Claims] (1) A microwave amplifier gain stabilization circuit used in a microwave amplifier having a variable attenuator and an amplifier in a microwave circuit section, the attenuator control section controlling the variable amplifier and receiving a control signal, ROM that outputs the set attenuation amount to the above attenuator control section
1. A microwave amplifier gain stabilization circuit comprising: a gain setting unit using a gain setting section using (2) The microwave amplifier gain stabilizing circuit according to claim 1, wherein the control signal is a frequency setting signal. (3) The microwave amplifier gain stabilizing circuit according to claim 1, wherein the control signal is a temperature detection signal. (4) The microwave amplifier gain stabilizing circuit according to claim 1, wherein the control signal is a gain instruction signal. (5) The microwave amplifier gain stabilizing circuit according to claim 1, wherein the control signals are a frequency setting signal and a temperature detection signal. (6) The microwave amplifier gain stabilization circuit according to claim 1, wherein the control signals are a frequency setting signal, a temperature detection signal, and a gain instruction signal. (7) The microwave amplifier gain stabilization circuit according to claim 1, wherein the control signals are a frequency setting signal and a gain instruction signal. (8) The microwave amplifier gain stabilizing circuit according to claim 1, wherein the control signals are a temperature detection signal and a gain indication signal.