An attenuation improvement technology for ladder SAW/FBAR filters and duplexers employing cancellation circuit

Author

Iwaki, Masafumi ; Tsutsumi, Jun ; Endo, Yuki ; Nakamura, Hiroshi ; Satoh, Yoshio

Author_Institution

Taiyo Yeden Co., Ltd., Akashi, Japan

fYear

2011

fDate

10-13 Oct. 2011

Firstpage

751

Lastpage

754

Abstract

This paper describes a new method of attenuation improvement at an arbitrary frequency in an RF SAW/FBAR filter or duplexer. There are leakage signal paths between terminals of RF filters or duplexers through stray capacitance and inductive coupling. By cancelling the main path by secondary path with proper phase and amplitude, high attenuation can be achieved at an arbitrary frequency. We analyzed this concept in detail for a WCDMA Band-I duplexer for GPS-band attenuation. A 50-dB GPS-band attenuation was obtained without sacrificing other properties.

Keywords

ladder filters; radiofrequency filters; surface acoustic wave resonator filters; GPS-band attenuation; WCDMA Band-I duplexer; arbitrary frequency; attenuation improvement technology; cancellation circuit; duplexers; inductive coupling; ladder RF SAW-FBAR filters; leakage signal paths; stray capacitance; Attenuation; Band pass filters; Equivalent circuits; Inductors; Microwave filters; Resonator filters; Surface acoustic waves; Duplexer; Filter; GPS; Isolation; WCDMA;

fLanguage

English

Publisher

ieee

Conference_Titel

Microwave Conference (EuMC), 2011 41st European

Conference_Location

Manchester

Print_ISBN

978-1-61284-235-6

Type

conf

Filename

6101733