JPS60186111A - Variable phase shifting circuit - Google Patents

Abstract

PURPOSE:To obtain the variable phase shifting circuit which makes a phase shift with high precision and is suitable for monolithic integration by adding a gain control amplifier circuit to two outputs of an RC phase shifting circuit respectively. CONSTITUTION:The connection point 71 of a capacitor 3 and a resistance 4 is connected to a gain control amplifier circuit 30 equipped with a control terminal 32. The connection point 81 of a resistance 5 and a capacitor 6 is connected to a gain control amplifier circuit 31 equipped with a control terminal 33. Capacity values of the capacitors 3 and 6 are set to the same value, and resistance values of the resistances 4 and 5 are set equal to each other. Gains of both amplifier circuits 30 and 31 are controlled independently with high precision to obtain a high-precision phase shift output between output terminals 34 and 35 of both amplifier circuits 30 and 31. Thus, the variable phase shifting circuit which makes a shift with high precision and is suitable for monolithic integration is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a phase shift circuit, which is particularly applicable in a high frequency band (microwave band) and is suitable for monolithic integration that can shift the phase to high precision. It is related to phase circuits.

Prior Art and Problems FIG. 1 shows a conventional RC phase shift circuit. In the figure 1.2
is the input signal terminal, 6 is the first capacitor (C5), 4 is the first resistor (R1), s is the second resistor (R2), 6 is the @2 capacitor ((4), 7 and 8 are The first and second output terminals are shown respectively.This circuit is well known as a resistor,
By varying the value of R1 or the capacitor 1ttC++Ct, it is possible to obtain an output voltage with the same amplitude as the input signal VIIJ and whose phase is variable from 0 to 360c'. However, this is a case where the values of the first resistor R8, the second resistor R3, the first capacitor C8, and the capacitor C2 of @2 are respectively favorable. i.e. output terminal 7 in Figure 1,
If the voltage between 8 and 8 is taken as the output voltage, the output voltage is V. ut
, the phase θ of the output with respect to the input is IVout l ”' l ”outl−vOut2, respectively.
l = IV engineering NI ...... (given by ri.

However, V. utl and Vout□ represent the output voltage of the output terminal 7°8, and ω represents the angular frequency of the input signal, respectively. Let us now consider the case where this circuit is applied in the microwave band -8'. For example, if the frequency of the input signal V is ft'2GlZ,
Calculate the values of the resistor R1 and capacitor C required to obtain an output whose phase is shifted by 90 degrees with respect to the input. 90° to input
To shift the phase, from equation 0, (ωCR)2=1
・・・・・・It is necessary to add 761 ■. For example, if 500 Ω is given as the value of the resistor R that satisfies the formula, the value of the required capacitance C is approximately 0.16 PF, and the values of the resistor R and capacitance C are sufficiently large with current semiconductor integrated circuit technology. It must be a value that can be converted into

However, it is not possible to adjust the values of passive elements such as resistance and capacitance with high precision on a semiconductor integrated circuit.

Moreover, no specific circuit has been provided that can realize the phase shift circuit of the configuration shown in FIG. 1 with a resistor or an i-changed configuration using a semiconductor integrated circuit.

FIG. 2 shows a conventional variable phase shift circuit that can be made monolithic in the microwave band. 11 is an input signal terminal, 12 is a terminating resistor, 16 is a 90° hybrid circuit, 14° and 15 are first and second dual gate FET amplifiers, 16, 1
7 is the output voltage of the FET amplifier, 20 is the phase synthesizer. , 21 indicate output terminals. FIG. 6 shows the relationship between the output voltage vectors of the first and second dual gate FET amplifiers and the vector of the output voltage 21. The circuit of FIG. 2 and its operating principle will be briefly described in). A 90' hybrid circuit 16 formed of a microstrip line allows the input signal to have a phase of 0° and 90°, respectively.
°shifted signals together, first and second dual signals)
J' to the gate terminals of FET amplifiers 14 and 15, respectively.
L is input. The pressure levels of the output voltages 18 and 19 are adjusted by the gate control voltage terminals 16 and 17 of the first and second dual gate FET amplifiers, and are combined by a phase synthesizer. As can be seen from Fig. 3, the phase of the combined output terminal 210゜Ichisho vector d is
It can be varied by the magnitude of the absolute value of the voltage vectors A and B of 8°19. Here, a voltage with a constant output level can be obtained by changing the thickness of the absolute value of the pressure vector It will be done. Therefore, the phase of the output obtained by the 6J phase shifter shown in FIG. 2 can be varied from 0 to 901J.

Furthermore, a 90° hybrid and a 180' hybrid are combined, and the phase with respect to the input is Oo and 90', respectively.
.

By obtaining signals shifted by 180° and 270° and configuring a phase shifter in the same manner as in Figure $2, an output whose phase is variable from 0 to 66o0 can be obtained.

As a monolithic version of this browning phase shifter, G
Forming a dual gate FET amplifier on an aAs substrate,
There is an example of a 90° hybrid phase synthesizer implemented using a microstrip line. However, when the variable phase shifter is made monolithic, the following problems occur. 90' hybrid.

Since the phase synthesizer is implemented using a microstrip line, it requires a larger area than a semiconductor integrated circuit. There is also a need for technology for manufacturing microstrip lines with 'a' t% accuracy.

OBJECTS OF THE INVENTION The present invention aims to solve the problems of the prior art, and its purpose is to be applicable to commercial wave bands, particularly microwave bands, and to be able to shift the phase with high precision. and provides a malleable phase shift circuit suitable for monolithic integration.

Structure of the Invention The variable phase shift circuit of the present invention is similar to the conventional RC shown in FIG.
By adding gain control amplifier circuits to the first and second outputs of the phase shift circuit and controlling the gains of both amplifiers independently, a desired iJ can be achieved between the outputs of both amplifiers.
The phase shift output is increased to 5.

Embodiment of the Invention FIG. 4 shows the configuration of an embodiment of the phase shift circuit of the present invention, where 1 is the input signal voltage, 6 is the first capacitor (
CI), 4 is the first resistance (R2), 5 is the second resistance (R
2), 6 is the '2nd capacitor (C2), 71 and 81 are the first node terminal (N, ) and second node terminal (N2), respectively, and 0 and 61 are the first and second capacitors, respectively. Gain control amplifier circuits 32 and 33 are first and second gain control amplifier circuits, respectively.
Control terminals 34 and 35 of the gain control amplifier circuit are first and second output terminals, respectively.

Next, the operation of the circuit shown in FIG. 4 will be explained. 1st and 2nd body'! Since the operation of the RC phase shift circuit composed of '7N, CII C2 and the first and second resistors R1+R2 has been described with reference to FIG. 1, the explanation thereof will be omitted. In the configuration shown in FIG. 4, the first and second resistors and the first and second resistors are given equal values.

Now, the input signal voltage is V, the voltage at the terminal 11, the 10th node N, and the second node N2 is V2, and the output voltage at the first output terminal 64 and the second output terminal 35 is V. u
ti +VOut2, the gain fX of the first gain control amplifier circuit 60 and the second gain control amplifier circuit 61: A, , A2, then the heavy pressure V between the output terminal 34 and the second output terminal 35 of @1. ut becomes. That is, the output V. ut is shifted by phase θ with respect to the input. Therefore, by changing the gains A1 and A2 of the first gain side 41'tl amplification circuit 60 and the second gain control amplification circuit 61, the phase jit ji, iθ taro' can be obtained.

Here, in order to make the output voltage amplitude level equal to the input voltage amplitude level, from the formula (A:=1+(ωCR)2(1'+")...
(It is necessary to satisfy A. Also, since A, , A, ≧0...■, the range of possible values for the gain AHHAH is 0.
≦A2≦P 77 doors ・Mountain・・(O. Therefore, (Equation of V formula? 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 1 and 2 and The mouth range is (wa, (su, (from the Yu-style formula, IAn-1 (-)
θ≦yr −jan−′ (a+cR) −−(′jp
It becomes ωCR. This is a change of phase. FIG. 5 shows this voltage vector relationship.

As can be seen from the figure, by satisfying the conditions of gain A and A, -d(ri2), the output voltage vector deviation t = A, V, A2 The phase of V2 is 4r between the phases of color and 2.
: Changes while keeping 3k 1lljIi constant.

Next, as the first and second gain control amplifier circuits shown in FIG. 4, integration of various circuits that can control the gain with high precision has been realized at present. As an example of the basic configuration, FIG. 6 shows an example of a gain control amplifier circuit using a bipolar device that can be applied to the variable phase shift circuit of the present invention. The amplifier circuit shown in FIG.
'Resistors R1, ~R1y and transistors Trl~Tr3
connected to a differential amplifier consisting of a transistor Tr
The output Vout is taken out from the second collector. Two sets of amplifier circuits shown in Fig. 6 are used, and 30
, 31 are replaced with the input voltages V'IN of the node terminals 71 and 81, respectively, and the control terminals 32 and 3
3 is the respective control voltage vc, and output terminal 3
4 and 35 have their respective output voltages V. Take out the ut'1
- Do as you like. The gain of each amplifier circuit can be changed by changing the control voltage Vct to control the current flowing through the differential amplifier circuit.

As described above, by carefully changing the gain of the gain control amplifier circuit shown in FIG. 4, the 61 phase shift circuit of the present invention can shift the phase with high precision. Furthermore, the lζC phase shift circuit and gain control amplifier circuit shown in FIG. 4 can be sufficiently integrated for microwave band applications.

Effects of Investigation As explained above, the =I variable phase shift circuit of the present invention has a high accuracy with respect to the input by controlling the gain of the gain control amplifier circuit with high precision so as to satisfy the condition of equation (2). Accurately phase Kesif) - can be. Moreover, the circuit of the present invention has 1
It has a small circuit configuration, and in microwave band applications,
It has the advantage of being fully monolithic with a semi-rod integrated circuit. Since it has such advantages, it is effective for making a monolithic variable phase shift circuit single phase modulator applied in the microwave band.

[Brief explanation of the drawing]

Fig. 1 shows a conventional RC phase shift circuit, Fig. 2 shows a conventional variable phase shift circuit used in the micro U band, and Fig. 6 shows a conventional variable phase shift circuit used in the micro U band.
The figure shows the relationship between each output voltage vector of the variable phase shift circuit in Figure 2. 6 is a diagram showing a specific example of a gain control amplifier circuit. 1.2... Input signal terminal, 6... First Capacity (C+
7.4...First resistance (R1), 5...Second resistance (R2), 6...Second capacitance (C2), 7,8...
First and second output satin, 11...input signal terminal, 1
2... Termination resistor, 13... 90° hybrid circuit, 14, 15... First and second dual gate F
ET amplifier, 16, 17...first and second control voltage terminals, 18, 19...first and 81'52 output voltages, 20...phase synthesizer, 21...output terminal, 6
0°61...gain control amplifier circuit, 52, 53...
1st and 20th control terminals, 54, 35... 1st and 2nd output & IHI terminals, 71, 81... 1st and 2nd node terminals Patent Applicant: Japan Amishin Telephone Corporation Agent Patent attorney Kugo Tamamushi! Is (2 others) 1st concave Figure 2, Figure 3, Figure 4, Figure 5 θ2=jan-'(ωCR)

Claims (1)

[Claims] One end of the capacitance of (ll?jJJ1 is connected to a signal input terminal, and the other end of the first capacitor is connected to the input of a first gain control amplifier having a first resistor and a terminal on the gain side. Connect to the first
A second gain control amplifier having the other end of the resistor grounded, one end of the second resistor connected to the input terminal, and the other end of the second resistor connected to one end of the second capacitor and the gain control terminal. , the other end of the second capacitor is grounded, and the values of the first and second resistors are the same, the values of the first and second resistors are the same, and the other end of the second capacitor is grounded. A variable phase shift circuit characterized in that an output is obtained as a voltage between an output terminal of a first gain control amplifier and an output terminal of the second gain control amplifier. (2) The gains of the first and second gain control amplifiers are A and A2, respectively, and the first and second gMk. If the value is 4c, the value R of the first and second resistors, and the angular frequency waveform of the signal input is ω, then “t=1 + (ωCR)” (1
-A,') The gains A and A2 of the first and second gain control amplifiers can be varied by applying respective control inputs such that the gains A and A2 of the first and second gain control amplifiers are satisfied. Variable phase shift circuit as described.