A Low Insertion Loss 140 GHz Terahertz Modulator Based on GaAs-Diodes

An ultra low insertion loss 140 GHz terahertz modulator based on GaAs-diodes is presented in this paper. In this modulator, two Schottky diodes are connected across a metal structure on the E-side of the waveguide. Terahertz amplitude modulation is achieved by applying a bias voltage to change the state of the diode, thereby affecting the propagation of terahertz waves in the waveguide. Through experimental testing, the modulator can achieve an ultra low insertion loss of 0.9 dB at 140 GHz, with a modulation depth of up to 99.9%.The ultra-low insertion loss and high switching ratio of the amplitude modulator have been achieved, resulting in significant performance improvement.