Circularly Polarized Transmitarray Design Using Characteristic Modes Theory

A novel strategy for the design of a circularly polarized (CP) transmitarray (TA) is proposed by resorting to the characteristic modes theory (CMT). The described TA working principle relies on the use of two transmitting unit cells that support a pair of characteristic modes characterized by either right-handed CP (RHCP) or left-handed CP (LHCP) scattered field. The measured results emphasized a notable 3 dB gain bandwidth of 15.22 % (7.77 GHz - 9.05 GHz) and a maximum TA gain of around 22 dBic at 8 GHz.