A Dual-Channel MEMS Amplitude Demodulator for On-Line Detection in Radio Relay Station

A dual-channel amplitude demodulator based on a micro-electromechanical systems (MEMS) approach for radio relay station on-line detection is proposed in this letter. This MEMS demodulator adopts a clamped-clamped beam to couple part of the signal from the main line to dual channels for on-line amplitude demodulation. The MEMS-based demodulation applies the square law of the thermal converter. The fabrication of the device is compatible with GaAs monolithic microwave integrated circuit process. Experiments show that the on-line MEMS demodulator has a return loss that is better than 20 dB, and an insertion loss of less than 0.5 dB up to 10 GHz. This design can realize direct demodulation of an amplitude modulation signal with a carrier frequency of 0.01-10 GHz.