HIGH Q MICROWAVE ACOUSTIC RESONATORS AND FILTERS

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.

[1]  G. K. Montress,et al.  Spectral purity of acoustic resonator oscillators , 1992, Proceedings of the 1992 IEEE Frequency Control Symposium.

[2]  G. R. Kline,et al.  Low Insertion Loss Filters Synthesized with Thin Film Resonators , 1987, IEEE 1987 Ultrasonics Symposium.

[3]  B. R. Mcavoy,et al.  Frequency stability of high-overtone bulk-acoustic resonators , 1992, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[4]  Kenneth Meade Lakin,et al.  Modeling of thin film resonators and filters , 1992, 1992 IEEE Microwave Symposium Digest MTT-S.

[5]  Kenneth Meade Lakin,et al.  Thin film bulk acoustic wave filters for GPS , 1992, IEEE 1992 Ultrasonics Symposium Proceedings.

[6]  M. M. Driscoll,et al.  Extremely low phase noise UHF oscillators utilizing high-overtone, bulk-acoustic resonators , 1992 .

[7]  Kenneth Meade Lakin,et al.  Equivalent Circuit Modeling of Stacked Crystal Filters , 1981 .