Coupling Reduction for Microstrip Antenna Array with Low RCS Performance

In this work, two kinds of metamaterials are designed to realize the reduction of radar cross section (RCS) and mutual coupling of two closely spaced microstrip antennas. For the surface wave coupling reduction, the electromagnetic bandgap (EBG) unit cells are added in the middle of the planar antennas. For the in-band RCS reduction, the artificial magnetic conductor (AMC) patches are chosen to compose the chessboard structure with destructive interference effect. Simulation results have shown that the isolation between the microstrip patch antennas is increased 7.6 dB, and the RCS value of array has decreased from 1.9 dBsm to −3.4 dBsm at 5.5 GHz simultaneously.