Off-band characteristics of small isolator for portable phones

Author

Takeda, S.

Author_Institution

Inf. Syst. Components Div., Hitachi Metals Ltd., Tokyo, Japan

Volume

3

fYear

1999

fDate

13-19 June 1999

Firstpage

1361

Abstract

The off-band attenuation characteristics of lumped element isolators for portable phones has been studied using the developed circuit simulator. The introduction of new parameters, circular-polarization occupation ratio /spl phi/ and ferrite filling factors /spl eta//sub r/, /spl eta//sub t/ along radius and thickness of garnet respectively, enabled us to realize the actual off-band characteristics by simulation. The second peak of attenuation near at 1.5f/sub 0/ reflects the residual inductance L/sub d/ due to /spl phi/ and /spl eta//sub r/. It has become evident that the attenuation pole near at 2f/sub 0/ corresponds to the ferromagnetic resonant frequency.

Keywords

UHF devices; circuit simulation; cordless telephone systems; ferrite isolators; telephone sets; attenuation pole; circuit simulator; circular-polarization occupation ratio; ferrite filling factors; ferromagnetic resonant frequency; isolator; lumped element isolators; off-band attenuation characteristics; portable phones; residual inductance; Attenuation; Circuit simulation; Conductors; Equivalent circuits; Garnets; Inductance; Isolators; Propagation losses; RLC circuits; Resonant frequency;

fLanguage

English

Publisher

ieee

Conference_Titel

Microwave Symposium Digest, 1999 IEEE MTT-S International

Conference_Location

Anaheim, CA, USA

Print_ISBN

0-7803-5135-5

Type

conf

DOI

10.1109/MWSYM.1999.779640

Filename

779640