High-frequency monolithic thin-film piezoelectric-on-substrate filters.

Autor: Abdolvand, Reza, Ayazi, Farrokh
Zdroj: International Journal of Microwave & Wireless Technologies; 2009, Vol. 1 Issue 1, p29-35, 7p
Abstrakt: A class of micromachined acoustic filters is presented in which the number of individual resonant structures is reduced to 1 (monolithic filter). This resonant structure is comprised of a stack of thin-film piezoelectric-on-silicon. Symmetric and anti-symmetric resonance modes (dual modes) of the silicon structure are piezoelectrically excited and coupled to realize a 2-pole narrowband filter. High-order lateral bulk acoustic resonance modes of a rectangular plate are utilized to design dispersed-frequency UHF filters fabricated on a single substrate. Thickness mode filters are also realized at GHz frequencies using a new interdigitated electrode design. Additionally, it is shown that the filter bandwidth can be controlled by changing the dimensions of the resonant structure and the electrode pattern. Narrowband lateral mode filters with filter Q’s larger than 300 at ~440 MHz and thickness mode filters with filter Q’s in the range of 150–900 at ~3.1 GHz are demonstrated. [ABSTRACT FROM PUBLISHER]
Databáze: Complementary Index