Low RCS Transmitarray Employing Phase Controllable Absorptive Frequency-Selective Transmission Elements

A low radar cross section (RCS) transmitarray is presented in this communication using phase controllable absorptive frequency-selective transmission (AFST) elements. The element consists of asymmetrical resonators with resistors to obtain an absorption–transmission–absorption response. The transmission phase within the transmission band can be controlled by rotating the AFST elements, achieving a 1 bit phase change. A low-RCS transmitarray using the developed elements is designed, fabricated, and measured. Compared with a reference transmitarray, the radiation performance of the low-RCS one is almost unchanged with a realized gain of 24.4 dBi. Significant RCS reductions have been realized for dual polarizations of the impinging electromagnetic (EM) waves. The 10 dB RCS reduction bandwidths are 18% and 14% for the lower and upper absorption bands, respectively.