A Terahertz Reconfigurable Transmitarray with Controllable Binary-Amplitude Elements

In this paper, a novel terahertz (THz) reconfigurable transmitarray (RTA) with 34-column controllable binary-amplitude element is designed. The single-layer element consists of double I-shape metal patches and an integrated varactor diode in the middle gap. By switching binary direct current (DC) voltages of the varactor, the incoming electromagnetic wave can be efficiently transmitted or strongly reflected, and the modulation depth of the transmission amplitude is greater than 15 dB in the 0.204-0.223 THz band. Each column of proposed RTA was independently configured to form reconfigurable patterns with air-like transparency or metal-like opacity zone for different beam direction. The
$\pm \mathbf{60}^{\circ}$
beam-steering capability with less than 3.6 dB gain fluctuation at horizontal plane was validated by theoretical calculations. Hence, the proposed transmitarray can be potentially used to implement easily-control, fast beam agility for terahertz-band applications.