Electronic countermeasure for OFDM-based imaging passive radars

Passive radars are notoriously robust to jamming because the receiver location cannot be detected. Moreover, the use of Orthogonal Frequency Division Multiplexing (OFDM)-based reference signals further improves the robustness against jammers. Nevertheless, deception/spoofing-type of jamming may still be possible. This article aims at proposing an electronic countermeasure (ECM) for OFDM-based passive radars with radar-imaging capabilities. Here, a target-on-board deception jammer is proposed that aims at protecting the target itself from being identified when passive radar imaging is used. A design of the architecture of the proposed target-borne jamming system is provided, which includes COmmercial of The Shelf (COTS) devices that are able to sample a broadband signal, modulate it in amplitude and phase, and retransmit it with a very short time delay. Theoretical and simulation results are also given proving that imaging and precise location of non-cooperative targets can be both affected by the presence of false and/or altered phase-modulated target echoes.