The year 1997 delivered several key innovations: The first properly designed three-resonator spring-coupled micromechanical filter, the invention of localized annealing for frequency trimming and Q<\/em> factor enhancement (later copied by many), and low velocity spring-coupling to retain reasonable spring dimensions when realizing narrow bandwidths for channel-select filters. The filters were all very low frequency–in the 455-kHz AM range–but were precursors to the much higher frequency filters to come a decade later.<\/p>\n\n\n\n
K. Wang and C. T.-C. Nguyen, \u201cHigh-order micromechanical electronic filters<\/a>,\u201d Proceedings<\/em>, 1997 IEEE International Micro Electro Mechanical Systems Workshop, Nagoya, Japan, Jan. 26-30, 1997, pp. 25-30.<\/p>\n\n\n\n
C. T.-C. Nguyen, \u201cHigh-Q<\/em> micromechanical oscillators and filters for communications (invited)<\/a>,\u201d Proceedings<\/em>, 1997 IEEE International Symposium on Circuits and Systems, Hong Kong, June 9-12, 1997, pp. 2825-2828.<\/p>\n\n\n\n
J. R. Clark, A.-C. Wong, and C. T.-C. Nguyen, \u201cParallel-resonator HF Micromechanical Bandpass Filters<\/a>,\u201d Digest of Technical Papers<\/em>, 1997 International Conference on Solid-State Sensors and Actuators, Chicago, Illinois, June 16-19, 1997, pp. 1161-1164.<\/p>\n\n\n\n
K. Wang, A.-C. Wong, W.-T. Hsu, and C. T.-C. Nguyen, \u201cFrequency-trimming and Q<\/em>-factor enhancement of micromechanical resonators via localized filament annealing<\/a>,\u201d Digest of Technical Papers<\/em>, 1997 International Conference on Solid-State Sensors and Actuators, Chicago, Illinois, June 16-19, 1997, pp. 109-112.<\/p>\n\n\n\n
K. Wang, F. D. Bannon III, J. R. Clark, and C. T.-C. Nguyen, \u201cQ<\/em>-enhancement of micromechanical filters via low-velocity spring coupling<\/a>\u201d Proceedings<\/em>, 1997 IEEE International Ultrasonics Symposium, Toronto, Ontario, Canada, Oct. 5-8, 1997, pp. 323-327.<\/p>\n","protected":false},"excerpt":{"rendered":"