JPH06273513A - Radar system - Google Patents

Abstract

PURPOSE:To allow the radar system to transmit and receive under perfectly jam-free state by providing a switch for selecting any one of a plurality of phase shifters having different phase shift to be connected with an auxiliary antenna. CONSTITUTION:A signal received by a main antenna 1 is subjected to frequency conversion and level regulation by a receiving signal processing circuit 2 and then fed through an input complex subtractor 4 in a jam removing circuit 3 to a weight operating unit 5. A signal received by an auxiliary antenna 6 is also subjected to frequency conversion and level regulation by a receiving signal processing circuit 7. If a detecting circuit 9 detects residual jam when a phase shifter 10 is connected with the antenna 6, switches 12, 13 select a second phase shifter 11 having phase shift different from that of the phase shifter 10. The detecting circuit 9 sustains detection of residual jam even during that interval and when no residual jam is detected due to change of the incident angle of jam to the antenna, the system is reset to a state where the first phase shifter 10 is selected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar device having an interference wave removing circuit.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram showing a conventional radar device of this type, and the structure will be described below along the flow of signals. A signal received by the main antenna 1 (hereinafter referred to as a main channel signal) is frequency-converted by a reception signal processing circuit 2,
The level is adjusted and input to the interference wave elimination circuit 3 and the complex subtractor 4
Is input to the weight calculator 5. On the other hand, a signal received by the auxiliary antenna 6 (hereinafter referred to as an auxiliary channel signal) is also frequency-converted and level-adjusted by the reception signal processing circuit 7 and input to the weight calculator 5. The weight calculator 5 outputs a weight value according to the amplitude / phase of the interfering wave by comparing the main channel signal and the auxiliary channel signal. The complex multiplier 8 modulates the auxiliary channel signal with the weight value so as to have the same amplitude and phase as the interfering wave component mixed in the main channel signal. Then, the modulated signal is subtracted from the main channel signal by the complex subtractor 4 to remove the interfering wave component.

In the radar device constructed as described above,
The disturbing wave component that remains even after the subtraction operation by the complex subtractor 4 is input to the weight calculator 5 again, and the weight value calculation, the modulation by the complex multiplier 8 and the subtraction by the complex subtractor 4 are performed. A series of operations is performed as a feedback loop convergence operation. The time required for the completion of the feedback loop convergence operation is the phase relationship between the interference wave component in the main channel signal and the interference wave component in the auxiliary channel signal, which is caused by the change in the incident angle of the interference wave on the antenna. It is known that a large amount of time may be required due to the change of.

[0004]

In the conventional radar apparatus as described above, when the condition of the incident angle of the interfering wave on the antenna is bad, it takes time to complete the converging operation of the interfering wave removing circuit. However, there is a problem that the radar transmission and reception must be performed in the state where the interference wave is removed.

The present invention has been made in order to solve the above problems, and an object of the present invention is to obtain a radar apparatus capable of performing radar transmission / reception in a state in which interference waves are always removed completely.

[0006]

SUMMARY OF THE INVENTION A radar device according to the present invention comprises a detection circuit for detecting a residual unremoved wave at the output of the unresolved wave removal circuit and a phase shift amount connected to an auxiliary antenna.
The phase shifter is provided with two switches for selecting either one of the two phase shifters according to the detection result of the detection circuit.

[0007]

In the present invention, the interference wave removal residual at the output of the interference wave elimination circuit is detected, and when the elimination residual is detected, the phase shifter connected to the auxiliary antenna is switched to change the main channel signal in the main channel signal. By avoiding points where the phase relationship between the interfering wave component and the interfering wave component in the auxiliary channel signal is bad, it is possible to always perform radar transmission / reception with the interfering wave completely removed.

[0008]

【Example】

Example 1. FIG. 1 shows an embodiment of the present invention, in which 1 to 8 are exactly the same as the conventional device. 9
Is a detection circuit, 10 is a first phase shifter, 11 is a second phase shifter having a phase shift amount different from that of the first phase shifter 10, and 12 and 13 are switches.

The operation of the radar device configured as described above will be described. When the detection circuit 9 connected to the output of the interference wave detection circuit 3 detects the interference wave removal residual when the first phase shifter 10 is connected to the auxiliary antenna 6, the switches 12, 1
3 selects the second phase shifter 11. However, the removal residual detection by the detection circuit 9 continues during this period, and when the interference residual removal is no longer detected due to changes in the incident angle condition of the interference wave on the antenna, the first phase shifter is selected again. Return.

[0010]

As described above, according to the present invention, the interference wave removal residual at the output of the interference wave elimination circuit is detected, and when the elimination residual is detected, the phase shifter is shifted from the first phase shifter. By selecting the second phase shifter having a different phase amount, radar transmission / reception can be performed with the interference wave being completely removed.

[Brief description of drawings]

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

FIG. 2 is a configuration diagram showing a conventional radar device of this type.

[Explanation of symbols]

 1 Main Antenna 2 Received Signal Processing Circuit 3 Interfering Wave Removal Circuit 4 Complex Subtractor 5 Weight Calculator 6 Auxiliary Antenna 7 Received Signal Processing Circuit 8 Complex Multiplier 9 Detecting Circuit 10 First Phase Shifter 11 Second Phase Shifter 12 switches 13 switches

Claims (1)

[Claims] 1. A main antenna, an auxiliary antenna for removing an interference wave, a reception signal processing circuit connected to both antennas, and an interference wave removal circuit connected to the reception signal processing circuit, the side of the main antenna. In a radar device for removing an interfering wave mixed in a lobe region, a detection circuit for detecting a residual level of the interfering wave removal at the output of the interfering wave removing circuit and two phase shifts with different phase shift amounts connected to an auxiliary antenna. Device, and two switches for selecting one of the two phase shifters according to the detection result of the detection circuit.