Motorola Corporation

Thomas W McDonald

Lyle A Fajen

Robert B Malcolm

The output of a VCO, a referenced frequency signal and an offset frequency signal are mixed to provide a control signal for the VCO and a double offset frequency signal which is mixed with an output of the offset frequency source to provide a DC component having a positive polarity if the signals are inphase and the VCO is locked on one sideband and a negative polarity if the signals are out of phase and the VCO is locked on the other sideband. A sweep signal is activated and applied to the VCO in response to the VCO being locked onto the wrong sideband.

Apparatus and method for locking a PLL onto a selected offset frequency

In a target to be towed by a vehicle, such as an airplane or the like, a radar transmitter and receiver each having separate antennas mounted in spaced apart relation at the front and back of the target, said transmitter being periodically pulsed and said receiver being turned on periodically at a given time after each pulse to produce a generally ellipsoidally shaped, shell-like sensitive volume around the target in which the radar will sense bullets, and the receiver being further constructed to sense only positive Doppler signals so that only bullets entering the sensitive volume will be scored.

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Scottsdale, AZ, United States of America

Thomas W McDonald