A C-Band MEMS Frequency Discriminator With High Sensitivity and Linearity

This letter reports a C-band MEMS frequency discriminator with high sensitivity and linearity. The structure of the proposed discriminator is fabricated using GaAs Microwave Monolithic Integrated Circuit (MMIC) technology. The frequency discriminator consists of one dual-band power divider, one dual-band power combiner, one delay-line and the final MEMS thermoelectric power sensor. The purpose of the designed structure is to provide an ultra-wide working frequency band and simultaneously improve sensitivity and linearity. Both on-chip detector and packaged one are tested. S-parameter measurement illustrates good impedance matching covering 4-8 GHz. The frequency sensitivities of on-chip detector are 0.52 mu/MHz @ 17 dBm, 0.85 mu V/MHz @ 20 dBm and 1.66 mu V/MHz @ 23 dBm, while sensitivities of the packaged one are 0.43 mu V/MHz @ 17 dBm, 0.84 mu V/MHz @ 20 dBm and 1.48 mu V/MHz @ 23 dBm, respectively. The experiment of response time shows that the rise time and fall time of on-chip detector are about 670 mu s and 550 mu s, while the corresponding times of the packaged one are about 980 mu s and 730 mu s.