Improved synthetic aperture radar micro‐Doppler jamming method based on phase‐switched screen

Target micro‐motions such as rotation and vibration introduce phase modulation, termed as micro‐Doppler (m‐D) effect, onto synthetic aperture radar (SAR) signals. This causes ghost targets in the reconstructed SAR images. Inspired by this unique characteristic, a passive‐jamming method based on m‐D was developed for SAR. The m‐D jamming method utilised a rotating reflector to intentionally generate ghost targets as jamming strips on the SAR image so as to protect certain areas. The m‐D jamming method based on a single rotating reflector can only generate a long jamming strip along the azimuth direction but located in a finite number of range cells, which restricts the region of protected scene. In this study, an improved m‐D jamming method based on phase‐switched screen (PSS) is proposed, which combines the advantage induced by the PSS modulation and the usefulness of the m‐D jamming. By controlling the modulating frequency and waveform of the PSS, the jamming strip is enlarged along the range direction. Theoretical analyses and simulation results verify the validity of the proposed method.