JPH0583070A - Phase control circuit - Google Patents

Abstract

PURPOSE:To easily attain attenuation control for phase control with high accuracy by branching an input signal, varying respective phases and amplitudes so as to output a signal with a desired phase. CONSTITUTION:One of input signals distributed by a distributer 21 is further distributed by a 90 deg. distributer 23 to be signals having a phase difference of 0 deg. and 90 deg. respectively. A signal of the 0 deg. component is subjected to a prescribed attenuation by a fixed attenuator 24 and the result is inputted to a 90 deg. synthesizer 26. A signal of 90 deg. component passes through an attenuator 25 and the signal is inputted to other port of the 90 deg. synthesizer 26. As soon as a signal of 0 deg. phase is outputted from a port A of the 90 deg. synthesizer 26, a signal of 180 deg. phase is outputted. The amplitude of the vectors has a difference by using a control circuit 28 to change the attenuation rate of the attenuator 25. A signal via a phase shifter 22 is inputted to a port B of a synthesizer 27 and this signal has a phase of 90 deg. by using the phase shifter 22 with respect to a signal of 0 deg. phase inputted to a port C via the port A of the 90 deg. synthesizer 26. The synthesizer 27 synthesizes the vectors and a signal subjected to a required phase change is outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase control circuit that changes the phase of a microwave signal, and more particularly to a circuit that corrects minute phase fluctuations due to ripples in the power supply, fluctuations in the input, and the like.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram showing a conventional phase control circuit. In the figure, reference numeral 1 is a 90 ° distributor, which distributes an input signal and supplies it to attenuators 2 and 3 in the subsequent stage. Four
Is a combiner for combining the signals from the attenuators 2 and 3,
Further, 5 and 6 are control circuits for controlling the attenuation amounts of the attenuators 2 and 3, respectively, and 7 is a terminator.

Next, the operation will be described with reference to the vector diagram of FIG. The input signal is distributed by the 90 ° distributor 1 into components having a 90 ° phase difference, and becomes a vector a and a vector b. And the vector a is the attenuator 2,
Further, the vector b is input to the post-stage combiner 4 via the attenuators 3, respectively. Here, when the attenuators 2 and 3 have the same amount of attenuation, the vector c having a phase of 45 ° is output as the combiner. It is output from 4.

To obtain a signal whose phase is delayed by α ° with respect to the signal c having a phase of 45 ° as the output signal, the magnitude of the vector a is sin (45 ° -α) and the magnitude of the vector b is Is controlled by the attenuators 2 and 3 so as to be cos (45 ° -α), and the synthesizing unit 4 synthesizes them. The combined output thus obtained is shown in vector d in FIG.

When the phase change amount α is small, the control of the magnitudes of the vectors a and b can be approximated by a straight line. In the above example, it is necessary to decrease the vector a by β and increase the vector b by β. Phase control can be performed with accuracy. Here, β = sin α≈α radians.

[0006]

Since the conventional phase control circuit is constructed as described above, the attenuation amounts of two components of 0 ° component (vector b component) and 90 ° component (vector a component) are respectively set. It is necessary to control, and it is necessary to balance the control of the attenuation amount between the two systems with high accuracy. Especially, if the target phase change amount α is small, the change amount of the attenuation amount is small, so the balance is further improved. There was a problem that it was difficult to take.

The present invention has been made in order to solve the above problems, and provides a phase control circuit which can easily and accurately balance the control of the attenuation amount and can output a stable signal. It is an object.

[0008]

The phase control circuit according to the present invention distributes one of the distributed input signals by 90 ° and controls the attenuation amount so that each has a predetermined amplitude.
° Attenuation control means for combining and outputting a first signal having a predetermined phase and amplitude, and the other of the distributed input signals, a second having a 90 ° phase difference from the first signal.
And a phase shifter for outputting the signal of (1), and the first and second signals are combined to obtain an output signal having a desired phase and amplitude.

Further, a chain combiner on the input and output sides, a fixed attenuator for attenuating one branch signal with a predetermined attenuation amount to create a first signal, and a unit of 90 ° with respect to the first signal. A first phase shifter for producing a second signal having a phase difference, and a second phase shifter 180 ° in phase with respect to the first signal
And a variable attenuator for controlling the amplitude of the 180 ° phase-shifted branch signal to an arbitrary value to create a third signal, and outputs the first to third signals on the output side. The output signal having a desired phase and amplitude is input to the chain combiner.

[0010]

According to the present invention, the input signal is distributed, the signal having a predetermined phase and amplitude, the signal having a phase difference of 90 ° with respect to the first signal, and the signal having the phase difference of 1 with respect to the first signal.
A signal having a phase of 80 ° and a variable amplitude is created, and the above three signals are combined to obtain an output signal having a desired phase. Well, for this reason, control is easy and highly precise control can be performed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A phase control device according to an embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 21 is a distributor that receives and distributes an input signal, and 22 is a phase shifter provided between the distributor 21 and the combiner 27. Reference numeral 23 is a 90 ° distributor provided in the latter stage of the distributor 21, 23 is a 90 ° distributor, and a fixed attenuator 24 and an attenuator 25 are provided in the subsequent stage.
Are provided, and the outputs of these attenuators are input to the 90 ° combiner 26. The output of the 90 ° combiner 26 is input to the combiner 27 together with the output of the phase shifter 22. A control circuit 28 controls the amount of attenuation of the attenuator 25. In addition, 29 and 30 are terminators of the 90 ° distributor 23 and the 90 ° combiner 26. The above 90 °
The combiner 26 has the same function as the 90 ° distributor 23 and becomes a combiner or a distributor depending on the method of use.

Next, the operation will be described with reference to the vector diagram of FIG. One of the input signals distributed by the distributor 21 is further distributed by the 90 ° distributor 23 and 0 °.
And a signal having a 90 ° phase difference. Then, the signal of the 0 ° component undergoes a predetermined attenuation by the fixed attenuator 24, then
It is input to the 0 ° combiner 26. On the other hand, the 90 ° component signal passes through the attenuator 25 and is input to the other port of the 90 ° combiner 26.

In this way, the signal from the fixed attenuator 24 is output to the port A of the 90 ° combiner 26 in the 0 ° phase (vector a), and at the same time, the signal from the attenuator 25 is output in the 180 ° phase. It is output as (vector b). Therefore, when the attenuation amounts of the attenuators 24 and 25 are the same, the phase difference is canceled, the signal does not appear at the port A, and it is completely absorbed by the terminator 29.

Therefore, the control circuit 2 controls the attenuation amount of the attenuator 25.
The change in 8 causes a difference between the magnitudes of the vector a and the vector b, and thereby a signal having a phase difference of 0 ° or 180 ° at the port A of the 90 ° combiner 26 is obtained.

On the other hand, the signal passed through the phase shifter 22 is input to the port B of the combiner 27, which is 90 °.
Port C of synthesizer 27 via port A of synthesizer 26
It is set by the phase shifter 22 so as to have a phase of 90 ° with respect to the 0 ° phase signal input to the. This signal becomes as shown in vector c in FIG.

Then, the synthesizer 27 synthesizes the vector c and the vector a (or the vector b) shown in FIG. 2, and the signal which has undergone the necessary phase change (± α) is synthesized by the synthesizer 27.
Will be output more. When vector a = vector b, only vector c is available.

As described above, according to this embodiment, the input signal is distributed, one of them is further distributed by using the 90 ° distributor 23, and one of the distributed signals is distributed through the fixed attenuator 24. Further, the other signal is input to the 90 ° combiner 26 via the attenuator 25 whose attenuation amount is variable by the control circuit 28, and is 90 ° in phase with respect to the output signal c of the phase shifter 22 and has a predetermined magnitude. Since the vector a (or b) having (amplitude) is created and the combiner 27 combines the vector c and the vector a (or b), the phase is controlled to ± α with 90 ° as the reference. The phase can be controlled only by controlling the attenuation of one system, and is easier than the two-system (0 ° and 90 °) control in which the phase is controlled to ± α with 45 ° as the reference, as in the conventional example. Moreover, the control balance of the attenuation amount can be taken with high accuracy.

In the above embodiment, a 90 ° distributor is used, but a chain combiner may be used. That is, FIG. 3 shows a second embodiment of the present invention. In the drawing, 31 is an input side chain combiner functioning as a distributor, and 32 is an output side chain combiner functioning as a combiner. The output ports 4 to 4 are connected to the chain combiners 31 and 32.
6 and input ports 7 to 9, a fixed attenuator 33 is provided between the ports 4 and 7, a phase shifter 34 is provided between the ports 5 and 8, and further between the ports 6 and 9. Is provided with a phase shifter 35 and an attenuator 36, and the attenuation amount of the attenuator 36 is controlled by a control circuit 37.

Next, the operation will be described. First, the basic operation of the chain combiner will be explained. Now, when the respective ports of the chain combiners 31 and 32 are directly connected and the amplitude and phase of the signal at each port are not externally controlled, they are input to the chain combiner 31. The signals have equal amplitude and a predetermined phase difference, and are output from port 4, port 5, and port 6. The amplitude and phase difference of each signal are the same, and the chain combiner 31
When input to the chain combiner 32 having the same characteristics as the above, the signals input from the respective ports 7, 8 and 9 are combined, and a signal having the same amplitude as the input signal is output. FIG. 4 shows the state of vector combination of signals in the chain combiner 32. In the figure, a is a port 7 input signal (vector), b is a port 9 input signal (vector), c
Indicates a port 8 input signal (vector).

Next, when the amplitude and phase of the signal are controlled between the chain combiners as shown in FIG. 3, the phase of the signal from the port 4 of the input side chain combiner 31 is used as the reference (0 °). , The phase of the signal of the port 5 is set to 90 ° by the phase shifter 34 and the phase of the signal of the port 6 is set to 180 ° by the phase shifter 35.
When the fixed attenuator 33 and the attenuator 36 are inserted into the port 6 and input to the chain combiner 32, the same effect as the phase control according to the first embodiment can be obtained. FIG. 5 shows how vectors are combined in the chain combiner 32. In the figure, vector a is the input signal from port 7, vector c
Is the input signal from port 8 and vector b is the input signal from port 9. As can be seen from FIG. 5, the vector a
By changing the amplitude of the vector a by the attenuator 36, a vector (a- having a phase of 0 ° or 180 ° while having an arbitrary amplitude from the composition of the vector a and the vector b) is obtained.
b) is obtained. And this vector (ab) and 90
Since the phase vector c is combined, a signal whose phase is controlled by ± α is output to the output of the chain combiner 32.

The arrangement of the attenuator and the phase shifter arranged between the ports is not limited to this, and may be any arrangement that can obtain three types of phase differences and amplitude relationships.

[0022]

As described above, according to the phase control circuit of the present invention, the input signal is distributed and a 90 ° phase difference is generated between the signal having a predetermined phase and amplitude and the first signal. And a signal having a phase of 180 ° with respect to the first signal and having a variable amplitude, and combining the three signals to obtain an output signal having a desired phase. Therefore, only one system is required to control the attenuation amount, and there is an effect that stable and highly accurate phase control can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram of a phase control circuit according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of the phase control circuit according to the embodiment of the present invention.

FIG. 3 is a block diagram of a phase control circuit according to a second embodiment of the present invention.

FIG. 4 is a diagram for explaining the operation of the chain combiner of the phase control circuit according to the second embodiment of the present invention.

FIG. 5 is a diagram for explaining the operation of the phase control circuit according to the second embodiment of the present invention.

FIG. 6 is a block diagram of a conventional phase control circuit.

FIG. 7 is a diagram for explaining the operation of a conventional phase control circuit.

[Explanation of symbols]

 1 90 ° distributor 2 attenuator 3 attenuator 4 combiner 5 control circuit 6 control circuit 7 terminator 21 distributor 22 phase shifter 23 90 ° distributor 24 fixed attenuator 25 attenuator 26 90 ° combiner 27 combiner 28 Control Circuit 29 Terminator 30 Terminator 31 Chain Combiner (Input Side) 32 Chain Combiner (Output Side) 33 Fixed Attenuator 34 Phase Shifter 35 Phase Shifter 36 Attenuator 27 Control Circuit

Claims (2)

[Claims] 1. A phase control circuit for distributing an input signal, controlling the amount of attenuation of the input signal, and then combining them to output a signal having a desired phase. A distributor for distributing the input signal and one of the distributors. An attenuation amount control means which receives an output as an input, distributes this by 90 °, controls the attenuation amounts so as to each have a predetermined amplitude, and then combines them by 90 ° and outputs a first signal having a predetermined phase and amplitude. A phase shifter which receives the other output of the distributor and performs a phase shift process so as to have a phase difference of 90 ° with respect to the first signal, and outputs a second signal; A phase control circuit comprising: a combiner having a second signal as an input. 2. A phase control circuit comprising an input side chain combiner for distributing an input signal to create a plurality of branch signals and an output side chain combiner for synthesizing phase-controlled branch signals. A fixed attenuator for attenuating a signal with a predetermined attenuation amount to create a first signal having a predetermined amplitude and phase; and a phase of one branch signal is 90 degrees with respect to the first signal.
° A first phase shifter that shifts the phase to create a second signal, and the phase of one branch signal with respect to the first signal is 18
A second phase shifter for shifting the phase by 0 °; and a variable attenuator for controlling the amplitude of the branch signal shifted by 180 ° to an arbitrary value to create a third signal, A phase control circuit characterized in that a third signal is inputted to an output side chain combiner.