JPH06181407A - Feeding circuit for phased array - Google Patents

Abstract

PURPOSE:To vary the phase of all output signals with simple control by using an optical circuit so as to miniaturize a circuit having a power distribution function. CONSTITUTION:An optical frequency shifter 3 having a terminal to receive an electric signal and shifting a frequency of an optical signal by a frequency of the electric signal superimposed on the optical signal through the terminal is connected to one output terminal of a 2-distributer 2 of an optical circuit 8 and an N-optical signal distributer 4 distributing one optical signal into N(>=2)- sets of optical signals is connected to an output terminal of the distributer 4. Then a phase variable optical N-distributer 5 distributing one optical signal into N-sets of optical signals, giving a phase distribution to the N-sets of distributed optical signals and varying the phase distribution by external control is connected to the other output terminal of the N-optical signal distributer 4. Each one of the N-sets of outputs of the N-optical signal distributer 4 and the phase variable N-optical signal distributer 5 is connected to each of N-sets of 2-optical signal synthesizers 61-6N, and N-sets of photoelectric converters 71-7N detecting an electric signal superimposed on an optical signal are connected to the output terminals, from which N-sets of electric signals are outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phased array system in which a plurality of radiating elements are used to combine power in space, and a transmission signal is given power distribution by giving a specific amplitude distribution and phase distribution to each radiating element. The present invention relates to a phased array power supply circuit for supplying power.

[0002]

2. Description of the Related Art In a phased array system in which a plurality of radiating elements are arranged in an array and power is combined in space, the directivity of a radiant beam is determined by the amplitude distribution and phase distribution of the signals fed to the radiating elements. A radiation beam pattern is provided. Therefore, it has been considered as a promising system for applications in which the direction of the radiation beam is changed with time. In order to realize this directional beam, it is necessary to temporally change the phase distribution of the signal fed to each radiating element. For this reason, the power supply circuit has a configuration in which a power distributor for supplying power to each radiating element and a phase control circuit for each radiating element are arranged.

FIG. 2 shows the configuration of a conventional phased array power supply circuit for N radiating elements. In FIG. 2, 21 is a 1: N power distributor, 22 _{1 to} 22 _N are variable phase shifters, and 23.
Is an input terminal, and 24 _{1 to} 24 _N are output terminals. In this power supply circuit, the power distributor 21 distributes power by giving a necessary amplitude distribution to the N radiating elements. The variable phase shifters 22 _{1 to} 22 _N are controlled according to the change request of the radiation beam direction.

[0004]

In the power supply circuit for a phased array having such a configuration, when the number of radiating elements is in the order of hundreds or thousands in response to a request such as increase in transmission power, the power distributor 21 is turned off. There is an enormous problem when it is configured with an electric circuit or a microwave circuit. Further, since it is necessary to provide the variable phase shifters 22 _{1 to} 22 _N for all the radiating elements, the variable phase shifter 2 can be used as the number of radiating elements increases.
There is a problem that the number of 2 _{1 to} 22 _N increases, the scale of the control circuit also increases, and the control becomes complicated.

In order to solve the above problems, the present invention is for a phased array in which an optical circuit is used, a circuit having a power distribution function is downsized, and the phases of all output signals can be changed by simple control. An object is to provide a power feeding circuit.

[0006]

In order to achieve the above object, according to the present invention, a phased array is provided in which a transmission signal is given a specific amplitude distribution for power distribution, and the distributed power is supplied to the radiating elements corresponding to the number of distributions. A power supply circuit for phased array, the power supply circuit for phased array is configured by an optical circuit, and the optical circuit has a light source and an optical two-way splitter connected to an output end of the light source. An optical frequency shifter that has a terminal for inputting an electric signal at one output end and that can shift the frequency of light by the frequency of the electric signal to be superimposed on the light is connected through the terminal, The output terminal of the optical frequency shifter is connected to an optical N distributor for distributing one light N (≧ 2) lights, and one light is distributed to the other output end of the optical 2 distributor. It is divided into N pieces of light, and the phase is divided into the light divided into N pieces. And a phase variable optical N splitter capable of changing its phase distribution by external control are connected, and N outputs of the optical N splitter and N of the phase variable optical N splitter are connected. Outputs are connected to N optical two-wave multiplexers, one at a time, and N optical / wavelength detectors at the output ends of the N optical two-wave multiplexers detect the electric signals superposed on the light, respectively. An electrical converter is connected to the N light /
N electric signals are output from the output end of the electric converter.

[0007]

According to the present invention, one of the light split from the light source is shifted in frequency by the frequency of the microwave by the optical frequency shifter. The optical signal on which the microwave signal is superimposed is distributed in phase in the optical N distributor. In addition, the other of the two lights split from the light source is input to the phase variable optical N splitter, split into N waves, and the phase of the output light of the N waves has a relation of an arithmetic progression. Given the transition. The N outputs of the optical N splitter and the N outputs of the phase variable optical N splitter are input to the N optical 2 multiplexers, one output each. The output of each of the N optical 2 multiplexers is N
It is input to each photoelectric converter, converted into a microwave, and output.

[0008]

EXAMPLE FIG. 1 shows an example of the present invention. In FIG. 1, 1 is a light source, 2 is a 1: 2 light distributor, 3 is an optical frequency shifter, 4 is a 1: N light distributor, 5 is a 1: N phase variable light distributor, and 6 ₁ to
6 _N is a 2: 1 optical multiplexer, 7 _{1 to} 7 _N is an optical / electrical converter, 8
Is an optical circuit, 9 is a microwave input, and 10 ₁ to 10 _N are microwave outputs. A light which has a terminal for inputting an electric signal at one output end of the optical distributor 2 and which can shift the frequency of the light by the frequency of the electric signal superposed on the light through the terminal. The frequency shifter 3 is connected. An optical distributor 4 is connected to an output end of the optical frequency shifter 3, and one light is distributed to N lights and another N lights are distributed to the other output end of the optical distributor 2. A phase variable optical distributor 5 that can give a phase distribution to the emitted light and can change the phase distribution by external control is connected. The N outputs of the optical distributor 4 and the N outputs of the phase variable optical distributor 5 are respectively connected to _one optical multiplexer 6 _{1 to} 6 _N. The output terminals of the optical multiplexers 6 _{1 to} 6 _N detect the electric signals superimposed on the light respectively.
The individual optical / electrical converters 7 _{1 to} 7 _N are connected.

In the above structure, when the angular velocity of the light supplied from the light source 1 is Ω and the angular velocity of the microwave input signal is ω, the optical frequency shifter 3 shifts the frequency of the light by the microwave frequency. Frequency shifter 3
The angular velocity of the output light of is (Ω−ω). The optical signal on which the microwave signal is superimposed is in-phase distributed in the 1: N optical distributor 4. The other of the two light beams split from the light source 1 is input to the 1: N phase variable optical splitter 5,
A phase shift is given so that the phases of the output lights of the N waves are divided into waves and have a relation of an arithmetic progression. At this time N
The phase relationship of the individual output lights is (φ + i · Δθ) [i = 1 to 1
N]. The N outputs of the optical distributor 4 and the N outputs of the phase variable optical distributor 5 are 1 output each, and the N outputs are 2: 1.
The signals are input to the optical multiplexers 6 _{1 to} 6 _N. The input of the i (= 1 to N) -th 2: 1 optical multiplexer / demultiplexer is represented by the following equation.

A · cos {(Ω−ω) t} + b · cos
The output of the {Ωt + (φ + i · Δθ)} N pieces of optical multiplexer (6 ₁ to 6 _N) are input to each of the N optical / electrical converter (7 ₁ ~7 _N), is converted to a microwave power To be done. The heterodyne-detected light is converted into microwaves represented by the following equation.

B · cos {ωt + (θ + i · Δθ)} As can be seen from the above description, the phase distribution given to the optical signal distributed by the phase variable optical distributor 5 is directly the phase of the microwave output after the heterodyne detection. Given as a distribution.

In the case of the present embodiment, a phase distribution having an arithmetic progression relationship with the difference being Δθ is given, and when the radiating element of the phased array is fed with the phase distribution having this relationship, the phase distribution is changed from the direction perpendicular to the radiating surface. The beam will be emitted in a direction inclined by Δθ. Further, since the phase variable light distributor 5 has a function of changing Δθ by single control, it is possible to scan the direction of the radiation beam by single control.

[0013]

As described above, according to the present invention,
The power supply circuit for the phased array can be greatly downsized, and the phase control of a large number of radiating elements can be simultaneously performed by a single voltage control, and the control mechanism can be extremely simplified.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a conventional phased array power supply circuit for N radiating elements.

[Explanation of symbols]

1 ... Light source, 2 ... 1: 2 light distributor, 3 ... Optical frequency shifter,
4 ... 1: N optical distributor, 5 ... 1: N phase variable optical distributor, 6
_{1 to} 6 _N ... 2: 1 optical multiplexer, 7 _{1 to} 7 _N ... Optical / electrical converter, 8 ... Optical circuit, 9 ... Microwave input, 10 ₁ to 10 _N
… Microwave output.

Claims (1)

[Claims] 1. A power supply circuit for a phased array, which supplies a specific amplitude distribution to a transmission signal and distributes the power, and supplies the power distributed to the radiating elements corresponding to the number of distributions. The optical circuit has a light source and an optical two-divider connected to an output end of the light source, and the optical circuit has a circuit for inputting an electric signal to one output end of the optical two-divider. An optical frequency shifter having a terminal and capable of changing the frequency of the light by the frequency of an electric signal superimposed on the light via the terminal is connected, and one light is output to the output end of the optical frequency shifter. Is connected to N (≧ 2) pieces of light, and one light is divided into N pieces of light at the other output end of the light 2 divider, and N pieces of light are divided into N pieces of light. It is possible to give a phase distribution to the distributed light, and A phase variable optical N splitter that can be changed by control from a unit is connected, and the N outputs of the optical N splitter and the N outputs of the phase variable optical N splitter are 1 each. Is connected to an optical 2 multiplexer, and N optical / electrical converters for detecting electric signals superimposed on the light are connected to output terminals of the N optical 2 multiplexers,
A power supply circuit for a phased array, wherein N electric signals are output from the output terminals of the N photoelectric converters.