Wavelength-Scale Focusing Transducer Based on Suspended Aluminum Nitride Thin Film

A wavelength-scale focusing transducer based on suspended Aluminum nitride (AlN) piezoelectric thin film are designed, simulated and fabricated. The one port device was simulated and analyzed to verify the device focusing performance. Two-port acoustic delay line under different electrical configuration was simulated, fabricated and analyzed to evaluate the electro-acoustic transduction capability of the transducer. According to the simulation and measurenment results, the transducer can produce the expected focused gaussian lamb beam with a beam waist of 5 µm which is half of the wavelength. The insertion loss of 32.16 dB at 824.13 MHz proves the efficient electromechanical transduction capability of the transducer. The transducer is the potential component in phononic integrated circuits (PnICs).