A micromechanical resonating RF mixer

Abstract

An arrangement of microelectromechanical IPSonators is considered as a filtering mixer for RF signals. The mixing is based on the nonlinear (second-order) forcevoltage relationship of capacitive transducers that are used for electrical drive and readout of the resonator. Measured and simulated results are shown for the first prototype devices with a transducer gap of 1 pm. With the gap reduced to 100 nm, the approach is expected to reach a good mixer performance for RF frequencies up to 1 GHz. Namely, with 50 il source impedances, the combined insertion and conversion loss is expected to drop below 10 dB. The loss drops further when impedance transformation is used to raise the RF and LO source impedances seen by the resonator.