Wideband RCS suppression based on FSS structures for millimeter applications

In order to reduce the radar cross section (RCS) over a wide frequency range, two new designs are proposed and compared. For the design purposes, frequency-selective surfaces (FSS) have been applied due to their notable electromagnetic characteristics including reflection phase variations with frequency. Three different FSS unit cells are designed including large and small circles and multi-resonance square, to achieve 180+37° reflection phase difference over a wideband frequency range. Two different configurations using combinations of the three cells are examined in terms of the reflection phase difference. Numerical results of proposed designs show that those can cover monostatic RCS reduction of 44% and 51.4%, respectively.