A Broadband Artificial Magnetic Conductor Reflecting Screen and Application in Microstrip Antenna for Radar Cross-Section Reduction

A miniaturized artificial magnetic conductor (AMC) reflecting screen with broad bandwidth (12.1-20.5 GHz, 51.5%) and polarization independence is proposed, which is arranged in a chessboard-like screen by combining two different square AMC unit cells to obtain a wide effective reflection phase difference of 180° ± 30°. It is applied in a microstrip antenna for radar cross-section (RCS) reduction based on the principle of destructive interference. The simulated results indicated that the in-band RCS reduction is achieved from 13.4-20.5 GHz (47.7%), corresponding to the range of effective phase difference. Besides, the out-of-band RCS reduction is also realized in this letter. The domain of -10 dB RCS reduction is widened to 13.4-26.9 GHz (67.0%) because of the cancellation between approximately perfect electric conductors and AMC. Moreover, the radiation performance of the composite antenna is kept well. Finally, the proposed low-RCS microstrip antenna is manufactured and measured. The measured results coincide well with the simulated counterpart.