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Bulk acoustic wave‐coupled resonator filters: Concept, design, and application
Author(s) -
Shirakawa Alexandre A.,
Thalhammer Robert,
Jamneala Tiberiu,
Koelle Uli B.
Publication year - 2011
Publication title -
international journal of rf and microwave computer‐aided engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.335
H-Index - 39
eISSN - 1099-047X
pISSN - 1096-4290
DOI - 10.1002/mmce.20552
Subject(s) - resonator , passband , duplexer , microwave , electronic engineering , acoustics , wideband , umts frequency bands , engineering , materials science , band pass filter , electrical engineering , telecommunications , physics , antenna (radio)
Abstract Bulk‐acoustic‐wave‐coupled resonator filters is an emerging technology that is capable of meeting increasingly ambitious demands of wireless applications by addressing performance, chip size, and die cost. This article outlines the fundamental design principles of these filters. A major consideration of filter design is the choice of the coupling structure between the two vertically stacked resonators. This can be either a multilayer Bragg coupler or a novel structure using a single layer of a very low acoustic impedance material. It is demonstrated how spurious modes are related to the dispersion diagram and how they affect the passband characteristics. For the suppression of these spurious modes suitable edge termination techniques are discussed. Based on optimized coupler performance and known parasitic effects, we analyze circuit design methods for microwave filters and duplexers with specific passband, roll‐off, and wideband responses. We show as example a miniature 2.0 × 1.6 mm 2 Universal Mobile Telecommunication System (UMTS) Band1 duplexer fabricated using the coupler resonator technology. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011.