US 4,065,768 AGranted

Radar apparatus

AssigneeMitsubishi Denki Kabushiki Kaisha

InventorsTeruo Kondoh, Kazuhiro Ban, Akio Kawamoto, Yoshiki Masuno, Mitsuhiro Yoshida

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Abstract

A radar apparatus comprises a microwave head portion in which a solid state oscillator, such as a Gunn oscillator, is utilized to generate a transmitting signal wave to be transmitted toward a target as well as a local oscillation signal wave by which an intermediate frequency signal is obtained upon a receipt of a reflected wave from the target. A transmission-reception switch means connected to a hybrid coupler constitutes a switching means for switching the operation of the radar apparatus between a transmitting mode and a receiving mode. A signal processing portion is provided in which the instantaneous amplitude value of the intermediate frequency signal according to a phase variation of the intermediate frequency signal due to the movement of the target is obtained by sampling the intermediate frequency signal with sampling pulses, whereby the velocity and moving direction of the target are determined and, by combining such information, an alarm is actuated.

Claims38

Dependent claims

A radar apparatus, comprising:

a microwave head portion including an antenna adapted to transmit an electromagnetic wave of a first frequency and to receive a reflection wave from at least one target, an oscillator capable of selectively producing said first frequency and a second local oscillator frequency, said oscillator first frequency being connected to said antenna to provide said electromagnetic wave, control circuit means for controlling the time of generation of said first and second frequencies by said oscillator, and a mixer for providing an intermediate frequency signal upon receipt of said reflection wave of said first frequency and a signal wave of said second frequency from said oscillator;
an intermediate frequency amplifier circuit responsive to said intermediate frequency signal from said microwave head portion for amplifying said intermediate frequency signal;
and signal processing means responsive to said intermediate frequency signals from said mixer for developing conditional signals representative of conditions of said target, said signal processing means comprising, a sampling pulse generation circuit for producing sampling pulses each having a pulse width shorter than the period of said intermediate frequency signal, and a sample and hold circuit means responsive to said sampling pulses for sampling and holding the instantaneous amplitude values of said intermediate frequency signal.

Dependencies are inferred from the claim text.