High Q metal strip SSBW resonators using a SAW design
- 1 November 1990
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
- Vol. 37 (6) , 530-534
- https://doi.org/10.1109/58.63109
Abstract
An experimental study of metal strip surface skimming bulk wave (SSBW) resonators using a surface acoustic wave (SAW) design is presented. Characteristics of SSBW and SAW resonators fabricated with the same photolithographic mask are compared and discussed. High Q low-loss SSBW resonators are achieved using a conventional two-port SAW resonator design and taking special care of the distance L between both interdigital transducers, the metal thickness h/ lambda ( lambda =acoustic wavelength) and the finger-to-gap ratio. Best overall performance of the SSBW devices in this study is achieved at L=n lambda /2- lambda /4 (compared with L=n lambda /2- lambda /8 for SAW resonators), h/ lambda =1.6% (compared with 2% for SAW), and finger-to-gap ratio close to 1. The best device fabricated shows an unloaded Q of 5820 and an insertion loss of 7.8 dB at 766 MHz. The SSBW resonant frequency shows a stronger dependence on the metal thickness than the SAW one. This problem, however, is readily solved by frequency trimming using a CF/sub 4/ plasma etching technique. SSBW resonator can be trimmed by 0.2% down in frequency (compared with 0.05% for SAW) without affecting their performance.<>Keywords
This publication has 9 references indexed in Scilit:
- Harmonic operation of STW filtersPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2003
- Novel Surface Transverse Wave Resonators with Low Loss and High QPublished by Institute of Electrical and Electronics Engineers (IEEE) ,1987
- GHz SAW and STW Bandpass Filters Without Submicron Geometries Using Harmonic Group Type Unidirectional TransducersPublished by Institute of Electrical and Electronics Engineers (IEEE) ,1987
- SBAW Oscillators at 3 to 5 GHz RangePublished by Institute of Electrical and Electronics Engineers (IEEE) ,1983
- 2.2 GHz SH-Mode SAW Delay LinePublished by Institute of Electrical and Electronics Engineers (IEEE) ,1982
- Synchronous IDT SAW Resonators with Q Above 10,000Published by Institute of Electrical and Electronics Engineers (IEEE) ,1979
- Surface Skimming Bulk Wave, SSBWPublished by Institute of Electrical and Electronics Engineers (IEEE) ,1977
- Further Investigation of Shallow Bulk Acoustic Waves Generated by Using Interdigital TransducersPublished by Institute of Electrical and Electronics Engineers (IEEE) ,1977
- Bandpass Filters Employing Surface Skimming Bulk WavesPublished by Institute of Electrical and Electronics Engineers (IEEE) ,1977