Bulk Acoustic Wave CRF Design

Eden CORRALES, Pedro de PACO, Oscar MENENDEZ, Jordi VERDU

Antenna and Microwave Systems Group (AMS), Universitat Aut`onoma de Barcelona (UAB) Escola T`ecnica Superior d’Enginyeria, UAB Campus, Barcelona, Spain
E-mail: eden.corrales, pedro.depaco, oscar.menendez, [email protected]

Abstract. In a Coupled Resonator Filter (CRF) a set of passive layers allow partial coupling between its two resonators. This allows for much wider bandwidth filter responses than its predecessor, the Stacked Crystal Filter (SCF). This work presents an all-electrical model for the Coupled Resonator Filter and associates the acoustical coupling with an electrical impedance inverter between resonators. The resulting equivalent circuit makes it possible to directly apply classical filter synthesis techniques based on the coupling control between resonators.