Development of miniature filters for wireless applications

Author

Lakin, Kenneth M. ; Kline, Gerald R. ; McCarron, Kevin T.

Author_Institution

TFR Technol. Inc., Redmond, OR, USA

Volume

43

Issue

12

fYear

1995

fDate

12/1/1995 12:00:00 AM

Firstpage

2933

Lastpage

2939

Abstract

Miniature filters have been under development for wireless applications from 500 MHz to over 6 GHz using thin piezoelectric films on common substrates. This paper discusses recent results in the development of miniature filters using a solidly mounted resonator (SMR) concept wherein the acoustic resonator is isolated from the substrate with a sequence of quarter wavelength thick layers that form a reflector. The SMR concept is discussed in detail and applications to filters is presented. Ladder filters have been demonstrated with insertion losses in the 3 dB range using aluminum nitride films for the piezoelectric and appropriate substrates such as silicon, sapphire, and glass. The ladder filters reported consist of interconnected series and shunt resonators forming a monolithic structure on a single die of comparable size to an integrated circuit

Keywords

UHF filters; acoustic resonator filters; aluminium compounds; crystal filters; ladder filters; microwave filters; piezoelectric thin films; radio equipment; 3 dB; 500 MHz to 6 GHz; AlN; acoustic resonator; insertion losses; interconnected resonators; ladder filters; miniature filters; monolithic structure; piezoelectric film; reflector; solidly mounted resonator; wireless applications; Acoustic waves; Aluminum nitride; Glass; Insertion loss; Integrated circuit interconnections; Optical films; Piezoelectric films; Resonator filters; Semiconductor films; Silicon;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/22.475658

Filename

475658