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A flexible receiver architecture for multi-band Passive Bistatic Radar

In this paper a flexible receiver architecture is described for a Passive Bistatic Radar (PBR) that can exploit any of the many broadcast signals available in the frequency spectrum, going from the FM and VHF-UHF bands (DAB/DVB-T) to the S-band (WiFi/WiMax/LTE). Specific front-ends receiver sections are foreseen for each selected waveform of opportunity, while a common part of the system performs the I&Q demodulation and the Analog-to-Digital (A/D) conversion. The scheme can be used both for a direct I&Q conversion and for a double conversion (up-conversion stage from Radio Frequency-RF-to a high Intermediate Frequency -IF- and down-conversion from IF to Base Band -BB-) of the received signals for PBR applications. This allows to remove the image frequency even in the wide bandwidth occupied by the digital TV signals. A prototype of the proposed concept has been developed and fielded, with proper laboratory tests and real data acquisition campaigns, at DIET Dept. of the University of Rome “La Sapienza”. The results obtained with the receiver, in three possible configurations, are reported and discussed: FM-based PBR (for medium/long-range air targets surveillance), DAB/DVB-T (for medium range air and sea surveillance) and WiFi-based PBR (for short-range human target localization).