A balanced measurement and characterization technique for thermal-piezoresistive micromechanical resonators

A novel balanced two-port measurement technique capable of adjusting feedthrough signal has been proposed to demonstrate both cancellation and tuning of feedthrough levels for one-port thermally actuated resonator with piezoresistive sensing (thermal-piezoresistive resonator), therefore attaining clean frequency spectra and real resonance characterization. Conventional one-port thermal-piezoresistive resonators significantly suffer high transmission feedthrough and often necessitate post-data processing and de-embedding to extract pure resonance behavior. For the first time, the one-port thermal-piezoresistive resonators with longitudinally vibrating mode shape were tested using the proposed technique to offer the directly measurable resonator Q, motional impedance, and resonance frequency with an improvement of around 80 dB feedthrough reduction. This approach could be easily applied to any one-port thermal-piezoresistive resonator with much higher frequency, showing great potential to enable future sensor and RF applications.