Pulse Compression-Key to More Efficient Radar Transmission

Increased demand for greater detection ranges in radar systems is often thwarted by the transmitting tube peak power limitation which, for narrow pulse operation, is usually reached before the full average power capability of the tube is realized. The technique of pulse compression offers a means of increasing the average power available to illuminate radar targets without any loss at the receiver of the resolution needed for the tactical requirements of the system. This is accomplished by transmitting a wide pulse in which the carrier is frequency modulated and then, by proper signal processing methods, causing a time compression of the received signal to a much narrower pulse of high effective peak power. The spectra and time functions of a particular class of pulse compression signals are analyzed and the basis for compression filter design is derived. Test waveforms demonstrate the resolving capability of the pulse compression technique.