JP2000004268A - Phase shifter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phase shifter with which a phase shift amount can be set from the outside, setting accuracy is improved and signals or modulated signals from analog frequencies to micro-frequencies can be used as well. SOLUTION: This phase shifter is provided with 90 deg. distributor 1 for distributing an input signal to two signals having the phase difference of 90 deg., control part 2 for inputting the required phase shift amount and outputting a quadrature component corresponding to this amount as two control signals, two mixers 3 and 4 for respectively mixing the two control signals with two distributed outputs of the 90 deg. distributor 1, and synthesizer 5 for synthesizing and outputting the outputs of these mixers and an output signal shifting its phase in respect to the input signal is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase shifter (a device for shifting the phase of a signal to a required value) used in a transmission / reception unit for mobile communication and satellite communication.

[0002]

2. Description of the Related Art FIGS. 4 and 5 are block diagrams showing the structure of a conventional phase shifter. FIG. 4 shows an example using a multiplying circuit and a flip-flop circuit, and FIG. 5 shows an example using a delay circuit. In FIG. 4, reference numeral 11 denotes a distributor, 12 denotes a multiplier circuit connected to the minus output of the distributor 11, 13 denotes a flip-flop circuit connected to the other output of the distributor 11 and the output of the multiplier circuit 12, and Is the flip-flop circuit 1
3 is a control unit for controlling (setting the amount of phase shift). In FIG. 5, reference numeral 15 denotes a delay circuit including a delay element.

Next, this operation will be described. In FIG. 4, an input signal cos (2πft) having a frequency f and a phase φ
+ Φ) is divided into two by a distributor 11, one of which is supplied to a multiplier circuit 12 and the other to a flip-flop circuit 13. Assuming that the multiplication number of the multiplication circuit 12 is N (N = 2, 3,...), The frequency is multiplied by N in the multiplication circuit 12 and the multiplication signal c
os (2πNft) is supplied to the flip-flop circuit 13. The flip-flop circuit 13 latches the input signal using the multiplied signal as a timing signal, thereby generating an output signal cos (2πft + φ + △ φ) whose phase is shifted by Δφ with respect to the original input signal.
The phase shift amount △ φ is set to a required value by the multiplication number N and a control signal Sc (designating the position to be latched) from the control unit 14 that controls the flip-flop circuit 13. In FIG. 5, the input signal cos (2πft +
φ) is shifted in phase by 遅 延 φ by the delay circuit 15 to generate an output signal cos (2πft + φ + △ φ). The amount of phase shift Δφ is set to a required value according to the internal configuration of delay circuit 15 (the number and length of delay elements, etc.).

[0004]

Since the conventional phase shifter is constructed as described above, the phase shifter shown in FIG. 4 must use a logic circuit for the multiplication circuit and the flip-flop circuit and can be used. There is a problem that the signal is limited to a low frequency (currently about several tens of MHz or less) and cannot be realized from an analog frequency to a microwave frequency (several hundred MHz to several tens GHz). In addition, since the signal is operated while being saturated (clip), there is a problem that information of an amplitude component is lost in the case of a modulated signal or the like. Further, the phase shifter of FIG. 5 has a problem that the phase shift depends on the internal configuration of the delay circuit, and the accuracy of setting the phase shift amount is poor due to factors such as variations and changes in environmental conditions (such as temperature). was there. There is also a problem that it is difficult to externally set the phase shift amount.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a phase shifter in which the amount of phase shift can be externally set, the setting accuracy is good, and a modulated signal can be used. It is. Also, analog frequency ~
An object of the present invention is to provide a phase shifter that can use a signal of a microwave frequency.

[0006]

According to a first aspect of the present invention, there is provided a phase shifter for distributing an input signal into two signals having a phase difference of 90 degrees, and a required phase shift amount. A control unit for outputting two control signals corresponding thereto, two mixers for mixing the two control signals with two distribution outputs of the 90-degree distributor, and synthesizing the outputs of these mixers And a combiner for generating an output signal, the output signal having a phase shifted with respect to the input signal.

According to a second aspect of the present invention, in the phase shifter according to the first aspect, the 90-degree distributor, the control unit, the mixer, and the synthesizer are configured by hardware. It is characterized by the following.

According to a second aspect of the present invention, there is provided a phase shifter for dividing an input signal into two signals having a phase difference of 90 degrees by operation, and a required phase shift amount. A control signal generator that outputs two corresponding control signals, two multipliers that multiply the two control signals by two signals having a phase difference of 90 degrees, respectively, And an adder for adding and outputting the two signals, and generating an output signal whose phase is shifted with respect to the input signal.

A phase shifter according to a fourth aspect of the present invention is the phase shifter according to the third aspect, wherein the 90-degree phase shift operation section, the control signal generation section, the multiplication section and the addition section are implemented by hardware. Alternatively, it is characterized by being constituted by software.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 First, the operation principle of the phase shifter of the present invention, which is common to the first and second embodiments, will be described. Now, let the input signal be Acos (2πft + φ) (where A: amplitude, f: frequency, t: time, φ:
Phase), two signals having a phase difference of 90 degrees are expressed as Acos (2πft + φ), -Asin (2πft +
φ). When the control signals (Sc1 and Sc2) are set as Sc1 = cos △ φ and Sc2 = sin △ φ (where Δφ is the amount of phase shift), the output signal is obtained by mixing (multiplication) and combining (addition). Acos (2πft + φ) × cos △ φ−Asin (2
πft + φ) × sin △ φ = Acos (2πft + φ +
Δφ), and an output signal whose phase is shifted by Δφ with respect to the original input signal is generated. Control signals (Sc1, Sc
The relationship between 2) and the amount of phase shift Δφ can be represented by points on the circumference as shown in FIG.

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In FIG. 1, the whole is constituted by a hardware circuit, 1 is a 90-degree distributor, and 2 is a control signal (S
c1, Sc2) are connected to the two outputs of the 90-degree distributor 1 and the mixers to which the control signals Sc1 and Sc2 are respectively supplied, and 5 is connected to the outputs of the mixers 3 and 4 It is a synthesized device.

Next, the operation will be described. In FIG. 1, an input signal Acos (2πft + φ) having a frequency f and a phase φ is converted into two signals Acos (2πft + φ) and −Asin (2πft +) having a phase difference of 90 degrees by a 90-degree distributor 1.
φ) and supplied to the mixers 3 and 4 respectively. The control unit 2 generates two control signals Sc1 (= cos △ φ) and Sc2 (= sin △ φ) from the required phase shift amount Δφ, and supplies them to the mixers 3 and 4, respectively. In the mixers 3 and 4, multiplication of the two signals is performed, and Acos (2πft + φ) × cos △ φ and −Asin (2πft + φ) × sin △ φ are output and supplied to the synthesizer 5. In the synthesizer 5, 2
The two signals are added to generate an output signal Acos (2πft + φ + △ φ) whose phase is shifted by Δφ with respect to the original input signal. The relationship between the two control signals (Sc1, Sc2) and the amount of phase shift can be represented by points on the circumference as shown in FIG.

As described above, the phase shifter according to the first embodiment is constituted by a hardware circuit, and divides an input signal into two signals having a phase difference of 90 degrees by a 90-degree divider, and each of the signals is divided into two signals. Is mixed with a control signal by a mixer, and then synthesized to generate an output signal whose phase is shifted with respect to the original input signal. According to the phase shifter according to the first embodiment, since the setting accuracy of the phase shift amount depends on the accuracy of the DC voltage given as the two control signals, high accuracy can be obtained. The phase shift amount can be set externally by two control signals. Since the information of the amplitude, phase change (relative phase), and frequency of the input signal is maintained, it can be applied to various modulation signals. Furthermore, if the 90-degree distributor and the mixer are formed by an analog circuit, a microwave circuit device, or the like, they can be used in an analog frequency band to a microwave frequency band.

Embodiment 2 FIG. Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. In FIG. 3, the whole is constituted by an operation unit by hardware or software, 6 is a 90-degree phase shift operation unit, and 7 is a control signal (S
c1, Sc2), and 8 and 9 are control signal generators.
Two outputs of the 0-degree phase shift operation unit and the control signal Sc1
And Sc2 are supplied respectively, and 10 is a multiplier 8 and 9
Is supplied to the adder.

Next, the operation will be described. In FIG. 3, an input signal Acos (2πft + φ) having a frequency f and a phase φ is converted into two signals Acos (2πft + φ) and −Asin (2πft +) having a phase difference of 90 degrees by a 90-degree phase shift operation unit 6.
φ), and supplied to the multipliers 8 and 9, respectively. The control signal generator 7 generates two control signals Sc1 (= cos △ φ) and Sc2 (= sin △ φ) from the required phase shift amount △ φ, and supplies them to the multipliers 8 and 9 respectively. . The multiplication units 8 and 9 multiply the two signals, and output Acos (2πft + φ) × cos △ φ and −Asin (2πft + φ) × sin △ φ, respectively, and supply them to the addition unit 10. The adder 10 adds the two signals to generate an output signal Acos (2πft + φ + △ φ) whose phase is shifted by Δφ with respect to the original input signal. The relationship between the two control signals (Sc1, Sc2) and the amount of phase shift can be represented by points on the circumference as shown in FIG.

As described above, the phase shifter according to the second embodiment is constituted by an operation unit using hardware or software, and converts an input signal into two signals having a 90-degree phase difference by a 90-degree phase shift operation. The output signal is divided into signals, each of which is multiplied by a control signal and then added to generate an output signal whose phase is shifted with respect to the original input signal. According to the phase shifter according to the second embodiment, high accuracy can be obtained because the setting accuracy of the phase shift amount depends on the accuracy of the DC voltage given as the two control signals. The phase shift amount can be set externally by two control signals. Since the information of the amplitude, phase, and frequency of the input signal is maintained, it can be applied to various modulation signals. Further, it can be easily constituted by arithmetic means by hardware or software.

[0017]

As described above, according to the phase shifter of claim 1 or 2 of the present invention, the amount of phase shift can be set externally, the setting accuracy is good, and a modulated signal can be used. Further, signals of an analog frequency to a microwave frequency can be used.

According to the phase shifter of the present invention, the amount of phase shift can be set from the outside, the setting accuracy is good, and a modulated signal can be used. Further, it can be easily constituted by arithmetic means by hardware or software.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a phase shifter according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a relationship between a phase shift amount and a control signal in a control unit according to the present invention.

FIG. 3 is a block diagram showing a configuration of a phase shifter according to Embodiment 2 of the present invention.

FIG. 4 is a block diagram showing a configuration of a conventional phase shifter.

FIG. 5 is a block diagram showing another configuration of a conventional phase shifter.

[Explanation of symbols]

1 90-degree distributor, 2 control unit, 3, 4 mixer,
Reference Signs List 5 synthesizer, 690 degree phase shift calculator, 7 control signal generator, 8, 9 multiplier, 10 adder, 11
Distributor, 12 multiplying circuit, 13 flip-flop circuit, 14 control unit, 15 delay circuit.

Claims (4)

[Claims] 1. A 90-degree splitter for splitting an input signal into two signals having a 90-degree phase difference, a control unit for inputting a required phase shift amount and outputting two control signals corresponding thereto. It comprises two mixers for mixing the two control signals with two distribution outputs of the 90-degree splitter, respectively, and a synthesizer for synthesizing and outputting the outputs of these mixers. A phase shifter for producing a shifted output signal. 2. The phase shifter according to claim 1, wherein the 90-degree distributor, the control unit, the mixer, and the combiner are configured by hardware. 3. A 90-degree phase shift operation unit for dividing an input signal into two signals having a 90-degree phase difference by operation, and a control for inputting a required phase shift amount and outputting two control signals corresponding thereto. A signal generation unit; two multiplication units for multiplying the two control signals by the two signals having the phase difference of 90 degrees; and an addition unit for adding and outputting the two signals obtained by the multiplication. Generating an output signal having a phase shifted with respect to the input signal. 4. The phase shifter according to claim 3, wherein said 90-degree phase shift operation section, control signal generation section, multiplication section and addition section are constituted by hardware or software.