This project improves the Q-factors of piezoelectric aluminum nitride (AlN) resonators by detaching their electrodes and suspending them at close distance. These devices are then used to make high-Q filters. "Capacitive-piezo" transduction, as it is called, allows for simultaneous low motional impedance (10-1000 Ohm) and high-Q (Q>8,800) performance for AlN resonators at VHF and UHF frequencies. The main advantage of these devices over capacitive resonators is their much stronger electromechanical coupling, e.g., Cx/C0>1.0%, enabling kt^2*Q figures of merit exceeding those of other technology classes in the range of 100MHz-1GHz. This project aims to use these high-performance resonators to demonstrate self-switchable, low impedance channel-selecting filters. Such filters can operate with insertion losses of less than 2-dB, stop- band rejection exceeding 50-dB, and power handling capability for high out-of-band and in-band power.
Project end date: 08/24/15