Novel waveform for magnetron radar

Magnetron does not lend itself to pulse-compression. To achieve narrow range resolution it must transmit short pulses. For given peak-power, antenna-gain and rotation-rate, increasing energy-on-target can be achieved by increasing the pulse repetition frequency (PRF), which is ordinarily limited by the specified unambiguous range. The proposed pulse-train waveform unties the two. Transmitting the first or second out of each pair of pulses of a uniform pulse-train, according to a periodic code, can extend the unambiguous range considerably beyond what the original PRF determines. In the receiver the envelope-detected return-pulses are correlated with a corresponding mismatched bipolar pulse-train. In addition to extending the unambiguous range, this detection concept performs Marcum’s alternative integration scheme of “(signal noise) noise”, exploiting its benefits. Successful coastal trials with modified civil marine magnetron radar are described.