Direct path interference suppression in bistatic system: DTV based radar

Over the past 20 years, bistatic radar has been an emerging technology. One of the major problems in continuous wave bistatic radar is the direct path interference (DPI). The reflected signal from the target is received at the background of this interference; the target would be buried under the sidelobes of the DPI in the receiver circuit. The conventional solution to this problem is the use of an adaptive antenna, steering a null towards the interference. Unfortunately, this technology is most effective in quasi-stationary receivers. For surveillance radar, the null depth obtained is not enough. This paper proposes a new technique of DPI suppression, based on dynamic compensation. Some aspects of cross-polarisation isolation between the transmitter and receiver is also considered.