Piezoelectric MEMS resonator characterization and filter design

This thesis presents modeling and first measurements of a new piezoelectric MEMS resonator developed at Draper Laboratory. In addition, some simple filter designs incorporating the resonator with predicted performance parameters were analyzed, with a special focus on the suitability of using the Draper resonator to implement these filters. The four-element Butterworth Van-Dyke model, the traditional circuit model used to describe crystal resonators, was predicted to match the theoretically derived electrical behavior of the fundamental-mode resonance. A three-element "pi" network model was used to describe the overall test structure. Transformations and algorithms to convert measured s-parameter data into best-fit model parameters were developed and successfully tested on commercial thin film resonators. Measurement of the first Draper resonators was complicated by fabrication difficulties and a resulting large parasitic which only allowed low frequency longitudinal resonances to be observed. However, the observed resonances at 125.3 MHz and 148.3 MHz were found to vary with geometrical parameters as expected, providing evidence that the design is viable. Initial resonator Q was estimated to be 542. Filters were designed with estimated resonator parameters after process optimization. Three topologies, simple (coupled) ladder, dual resonator ladder, and full lattice, are described and the limits and tradeoffs among them are discussed given the Draper resonator properties. Numerical examples and an example filter-plus-resonator design process are provided. Manufacturing tolerances and their effect on resonator and filter parameters are discussed. Finally, some considerations when implementing an integrated filter bank are outlined.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• Kang, Joung-Mo, 1978-

Advisor dc:contributor.advisor

• Amy E. Duwel and Charles G. Sodini.

• Electrical Engineering and Computer Science.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/28418

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/28418