A Low-RCS Microstrip Antenna Using EBG and HIS Structure

A novel method aimed at reducing radar cross section (RCS) of microstrip antenna is presented in this paper. The stopband electromagnetic band-gap (EBG) is used to replace the metallic ground of the proposed antenna to reduce the out-of band RCS. Meanwhile, the high impedance surface (HIS) is applied to reduce RCS in the operation frequency by canceling out the reflected wave. Thus, a wide band RCS reduction can be realized in and out of antenna's operating frequency hand. Results indicate that in-band RCS is reduced as much as 2.5 dB compared to the reference antenna. At the same time, out-of band RCS is reduced due to the EBG structure, and has a maximum RCS reduction value of 19 dB. The whole hand of RCS reduction is from 2 GHz to 15 GHz. With distinct low-RCS characteristic and little effect on radiation performance, the proposed method will have an extensive application on designing antenna with a requirement of RCS control.