Benjamin Chieh Yu

US Patent:

6954121, Oct 11, 2005

Filed:

Jun 9, 2003

Appl. No.:

10/457737

Inventors:

Paul D. Bradley - Mountain View CA, US
Yury Oshmyansky - Camarillo CA, US
Benjamin Yu - Sunnyvale CA, US

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

H03H009/00

US Classification:

333187, 333133

Abstract:

An apparatus such as a thin film resonator has a bottom electrode, a top electrode, and a composite layer between the two electrodes. The composite layer includes a piezoelectric (PZ) layer having a first coupling coefficient and a coupling coefficient control (CCC) layer having a second coupling coefficient. By varying the relative thicknesses of the PZ layer and the CCC layer during the manufacturing process, the coupling coefficient of the resonator can be established (to any value between the first coupling coefficient and the second coupling coefficient) with minimal impact on resonant frequency. Further, it is relatively less difficult to fabricate the PZ layer and the CCC layer having the desired coupling coefficient (as a combination of the first coupling coefficient and the second coupling coefficient) compared to the difficulties of fabrication of a uniform PZ layer having the desired coupling coefficient.