Abstract: A Doppler radar employing a common antenna for transmitting and receiving. A single sideband modulator (SSBM) is employed in the transmitting circuit to offset the rf reference frequency during transmit time and to discontinue offset during receiver ON time. Through a coupler and isolators an attenuated portion of the rf reference signal is applied to the receiver mixer at gated intervals. The output of the mixer are signals which are free of undesired reflected transmitter signals.

Abstract: A Doppler radar having a single sense Doppler signal from the rf mixer. A single sideband modulator in a common antenna system for transmitting and receiving shifts the fore and aft beams to achieve a single sense Doppler signal. The use of the single sideband modulator results in a differential Doppler shift between fore and aft beams of only a few hundred knots, thereby permitting use of low cost components. A single sense Doppler also reduces the Doppler passband by a 2:1 factor which permits the power supply frequency to operate at a higher frequency than the receiver.