Abstract: Passive radar is confronted with serious multipath clutter problem. Therefore, it is necessary to suppress the direct wave and multipath clutter, and improve the signal-to-noise ratio(SNR) and signal-to-clutter ratio (SCR) of target as much as possible. To solve this problem, a space-time domain combination adaptive technology is proposed based on the establishment of spatial, temporal and carrier-domain signal model for passive radar. In the technology, the spatial domain adaptive beamforming is used to get nulling in the direction of strong multipath clutter. And then a transversal filter is designed to eliminate weak clutter. The proposed space-time domain combination adaptive technology is used to process the simulated and measured data by taking DRM digital AM broadcast based passive bistatic radar for example. And it is proved that the proposed technology is practical, which can overcome the shortcomings of insufficient array degree of freedom and the insufficient clutter nulling depth due to low clutter noise rate in the spatial adaptive beamforming method. Key

Key words: ordnancescienceandtechnology, passivebistaticradar, clutterrejection, adaptivefilter, OFDMwaveform