A Photonic-Assisted 2-D ISRJ Jamming Strategy for SAR With Self-Interference Cancellation

To address the issues of limited bandwidth, restricted operating frequency range, limited adjustability, and SI in existing radar jamming schemes, a photonic-assisted twodimensional (2-D) interrupted-sampling repeater jamming (ISRJ) scheme with self-interference cancellation (SIC) capability is proposed for synthetic aperture radar (SAR), and verified through hardware-in-loop simulation experiments. Based on a simple dual-parallel dual-drive Mach-Zehnder modulator (DP-DDMZM), the received linearly frequency modulated (LFM) radar signal is interrupted-sampled directly in RF domain without the need for frequency up/down conversion, analog-to-digital/digital-to-analog conversion, RF storage or algorithm processing. This real-time jamming scheme supports an operating frequency range of 0-40 GHz, an instantaneous bandwidth of 40 GHz. It enables independently tunable 2-D jamming by adjusting the frequency and duty ratio of the two periodic bias voltage (PBV) signals, while also effectively eliminating self-interference (SI) signal that poses a significant challenge to jamming systems. Experimental results show that the scheme can generate 25 fake targets in range-azimuth dimension and realize 20 dB suppression of SI signal with 500 MHz bandwidth centered at 12.5 GHz or 5.5 GHz. The comparison of jamming results with and without SIC demonstrates the necessity of the SIC module in the jamming system. The scheme has the advantages of multifunctionality, independent adjustability, simple structure, wide operating frequency range, and large bandwidth, making it valuable for future electronic warfare systems.