Design of A Low RCS 1 Bit Electronically Reconfigurable Transmitarray Antenna

A 1 bit electronically reconfigurable transmitarray antenna with out-of-band radar cross section (RCS) reduction is designed in this paper. The element consists of two layers separated by air, which are absorptive frequency selective transmission (AFST) layer and reconfigurable transmitarray (RTA) layer. Concretely, the AFST layer contains a bent metallic strip with a centrally loaded resistor to achieve out-of-band RCS reduction and in-band transmission performance. Furthermore, the RTA adopts an active receiving dipole and a passive orthogonal transmitting dipole to realize the 1 bit reconfigurable of the in-band radiation beam. Then, a 16×16-element transmitarray antenna is designed. For scattering, the bandwidths of 10-dB RCS reduction are 37% and 9.4%, respectively. For radiation, the realized gain is 19 dBi at 7.5 GHz, and the beam scanning covers ±60° with gain loss of 4.3 and 3.8 dB in the E- and H-planes, respectively.