Design and development of low radar cross section antenna using hybrid metamaterial absorber

An efficient approach is presented in this article, to reduce radar cross section (RCS) of a microstrip patch antenna, without affecting other radiation characteristics by the application of a novel hybrid metamaterial (MM) structure. The microstrip antenna is designed to operate at 4.2 GHz. Three different configurations of MM structures (ie, CB_1, CB_2, and hybrid) with splitted square and ring shaped two nonidentical MM cells are designed and critically analyzed in the range of 2-18 GHz. A hybrid MM configuration is chosen for the design and implementation of low RCS antenna due to its exceptional performance as compared to CB_1 and CB_2. The hybrid MM is organized in chessboard configuration, comprises of splitted square and ring shaped MM unit cell. The results show that proposed antenna gives substantially out of band RCS reduction from 6 to 18 GHz and the proposed antenna has a lower RCS than the reference antenna. Proposed antenna attains wideband bandwidth around 7.4 GHz (ranging 2.0-4.4 GHz, 7.8-9.1 GHz, and 14.3-18 GHz). The maximum reduction of -30.1 dBsm at 16.4 GHz is achieved in the hybrid MM structure impinged microstrip patch antenna. Finally, the fabrication and performance evaluation of MM loaded antenna is carried out. Moreover, measured results of the fabricated samples are closely matched with simulated results, which prove the effectiveness of the adopted approach for practical applications.