HIGH Q MICROWAVE ACOUSTIC RESONATORS AND FILTERS

TLDR

The study reports experimental results and modeling of high‑Q microwave acoustic resonators and filters for oscillator and frequency‑control applications. The devices use aluminum nitride transducers on Z‑cut sapphire substrates. Overmoded resonators achieved Q ≈ 68 000 at 1.6 GHz with an inductive response suitable for oscillator feedback, and ladder filters built from them reached loaded Q > 40 000 with a 76 kHz bandwidth at 1.6 GHz.

Abstract

This paper presents recent experimental results and modeling obtained on high Q microwave acoustic resonators and filters for use in oscillators and other frequency control applications. Overmoded resonators have exhibited an FQ greater than 1 x 1014 Hz ( e.g. Q=68000 at 1.6 GHz) with a strong inductive response suitable for one-port and two-port oscillator feedback circuits. Ladder filters fabricated with overmoded resonators have loaded Q’s greater than 40000 with 76 KHz bandwidth at 1.6 GHz. Aluminum nitride films were use for transduction on Z-cut sapphire substrates.