Radar Cross Section Reduction for Microstrip Antenna Using Broadband Chessboard Artificial Magnetic Conductor Structure

In order to reduce radar cross section (RCS) of microstrip antenna, a chessboard structure composed of artificial magnetic conductors (AMC) structure is proposed. A novel equivalent circuit model is also introduced to facilitate the analysis and design of the Jerusalem cross AMC structure. Two AMC structures with different resonant sizes are designed to produce a 180°phase difference between the corresponding reflected waves, and destructive interference of backward scattering waves is achieved when a plane wave normally incidents on the microstrip antenna embedded in the chessboard AMC structure. As a consequence, the in-band and out-of-band RCS of the antenna is reduced dramatically from 12 to 24 GHz, and the maximal 36 dB RCS reduction is achieved without changing the performance of the antenna appreciably.