2-D Beamforming with a Terahertz Reconfigurable Transmitarray Using 1-Bit Transparency Modulation

A concise unit cell for terahertz-wave transparency modulation is proposed with a monolithically integrated Schottky barrier diode, achieving an on/off ratio greater than 10 at 215 GHz. Beamforming simulations applied to a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$50 \times 50$</tex> transmitarray based on the reconfigurable unit are conducted with a 1-bit transparency modulation method. Operating between 210 and 220 GHz, the transmitarray achieves a beam steering range of up to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\pm 70^{\circ}$</tex>, an average gain of 17.75 dB for normal radiations, a gain roll-off of less than 2.02 dB, and a maximum modulation loss of 8.91 dB, under the illumination of an isotropic point source. The proposed reconfigurable transmitarray also demonstrates effective simultaneous multi-beamforming.