Widely tunable MEMS ring resonator with electrothermal actuation and piezoelectric sensing for filtering applications

In this paper, we present the design, fabrication and testing of two-port ring microelectromechanical (MEMS) resonant devices with electrothermal actuation and piezoelectric sensing for wide tunable filter applications. The ring resonators have been fabricated in silicon carbide with top platinum electrothermal actuator and lead zirconium titanate piezoelectric sensor. The two-port transmission frequency response measurements have shown that the devices with a ring radius between 125. μm and 200. μm resonate in the frequency range 0.4-1.3. MHz, in the presence of tuning. By applying DC bias voltage in the range 4-10. V, a frequency tuning range of 330,000. ppm has been achieved. Devices of similar design but with longer ring radius, actuated under the same operating conditions, have shown a wider frequency tuning range.