Title :
Off-band characteristics of small isolator for portable phones
Author_Institution :
Inf. Syst. Components Div., Hitachi Metals Ltd., Tokyo, Japan
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;
Conference_Titel :
Microwave Symposium Digest, 1999 IEEE MTT-S International
Conference_Location :
Anaheim, CA, USA
Print_ISBN :
0-7803-5135-5
DOI :
10.1109/MWSYM.1999.779640
