A 140-GHz microstrip amplitude modulator based on Schottky Diodes

Terahertz modulation is always realized by the dynamic meta-surface with quasi-optical transmission mode, which limited the modulation speed and application in the integrated system. Here we propose a new way by combing the microstructure, active GaAs Schottky diodes, and microstrip to construct an active meta-chip that could realize low insertion loss, high modulation depth, and on-chip THz modulation. The diodes are controlled by the bias voltage to change the switching characteristics. Then, the resonant frequency is controlled to realize the amplitude modulation of THz (terahertz) waves. The simulation results indicate that the modulator can achieve an insertion loss of 2dB and a maximum modulation depth of 97.1 %.