Polyphase coded CW radar

The objective of the described CW radar resulted from the threat by anti-radiation-missiles. Instead of a scanning transmit beam with high gain an antenna with a broad illumination pattern is used. Therefore the radiation may be covered by a decoy transmitter all the time. The transmitted CW-signal is modulated by a polyphase code for range resolution. A multibeam receiver allows the direction estimation of targets. For detection the signals have to be integrated over a period corresponding to the usual scan period, e.g. 2 sec. The selection of the polyphase code in combination with code compression for unknown Doppler frequency shifts of target echoes are discussed.