A Novel Strategy to Compensate the Effects of Platform Motion on a Moving DRFM Jammer

Abstract

Digital Radio Frequency Memory (DRFM) is the core of any electronic jamming system. It is a high-speed sampling digital memory in which the radar signal itself is stored, modulated with jamming signals and then retransmitted to the threat. The signal transmitted back by the DRFM-based jammer is a simple replica of the original signal with some parameters manipulated. The DRFM capability is essential for jamming pulsed doppler radars. One of the open research problems in DRFM jammer design is the relative motion between radar, DRFM jammer and platform (an aircraft), and its effects on jammer's performance. It has been investigated that in case of relative motion between DRFM jammer and targeted radar, pulse width (PW) and pulse repetition interval (PRI) variation i.e., shrinkage or expansion will be observed depending upon direction of motion. This variation in PW and PRI is proportional to relative velocity, acceleration and jamming time of the DRFM jammer. In this paper, the effects of radial motion on a moving DRFM jammer are presented, and an efficient strategy is proposed to tackle them in the stand-in jamming (SIJ) scenario. MATLAB simulations and Verilog implementation of the proposed strategy is carried out to certify the analytical model. PW and PRI variation are employed as the principal performance metrics to quantify the proposed approach, by leveraging timing diagram analysis and PPI radar display.