A Direct Path Interference Cancellation Approach to Passive Radar Based on FM Radio transmitter

Target detection by non-cooperative illuminator is a research hotspot in electronic warfare field, with four countering' potential advantages. One of the major problems in bistatic radars with continuous waves is the direct path interference (DPI). The conventional solution to this problem is to use an adaptive antenna by steering null towards the interference. Unfortunately the null depth obtained by this technology is not enough for surveillance radar. First of all DPI based on FM broadcast transmitter in passive radar is analyzed in this paper. Secondly, a DPI cancellation approach based on adaptive fractional delay estimation (AFDE) is in detail introduced how to deal with this problem. Finally, a passive radar experimental system based on FM broadcast transmitter is discussed. Simulation results by applying real collected data show the provided method is effective