A super-regenerative microwave Doppler moving-target indicator

A reflex klystron oscillator is used as the microwave transmitter and superregenerative receiver in a Doppler radar designed to measure the relative speed of a moving target at distances of up to three hundred feet. It is shown that the klystron oscillation frequency must be kept within close limits, and the rate of oscillation decay must be suitably controlled, in order that the receiver sensitivity may be kept high. Experiments are described which further relate the sensitivity of the system to the change in oscillation frequency occurring during the quench cycle; in particular, by using a resonator quench, the effective power of the receiver is increased by over 50 dB above that obtained with a repeller quench. Road tests of the receiver have shown it to be of value as part of a collision-warning device for road vehicles.