A Miniature Isolator for 800 MHz Band Mobile Communication Systems

Youhei ISHIKAWA  Takekazu OKADA  Takashi KAWANAMI  Keiji OKAMURA  Toshio NISHIKAWA  

IEICE TRANSACTIONS on Electronics   Vol.E74-C   No.5   pp.1226-1232
Publication Date: 1991/05/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on the 3rd Asia-Pacific Microwave Conference)
Category: Passive Components

Full Text: PDF>>
Buy this Article

A surface mount device (S. M. D.) type miniature isolator has been developed. Its dimension is 6.8 6.9 4 mm3 and weight is 0.75 g. Both the volume and weight have been reduced to one-third compared with a conventional small model. A resin case and metalplated terminals on its surface are used to realize this configuration. By using a simplified simulation technique the most suitable ferrite size and the most suitable magnet are determined to minimize an insertion loss and to realize good temperature stability. Consequently, 0.8 dB insertion loss, 15 dB isolation and 14 dB return loss are obtained within 3 % bandwidth at 836.5 MHz in the practical operating temperature range between -25 and +75. Handling power capability of 2.5 W for forward input and 0.75 W for reverse input are achieved at +25.