SAW duplexers without λ/4 phase shifter for CDMA cellular phone systems

Author

Onzuka, Tatsunori ; Noguchi, Kazushige ; Yoshimoto, Susumu ; Yamamoto, Yasushi

Author_Institution

NRS Technol. Inc., Kawasaki, Japan

Volume

2

fYear

2004

fDate

23-27 Aug. 2004

Firstpage

966

Abstract

We have already reported a front-end SAW duplexer for Japanese PDC 800 MHz cellular phones with wide channel separation of 112 MHz between Tx and Rx band (Onizuka, T. et al., Proc. IEEE Ultrason. Symp., p.2101-4, 2003). We now describe an application of the SAW duplexer which has narrow channel separation by using SAW resonator in which arbitrary pole and zero frequencies are controlled by adding an external inductor and/or capacitor. For example US-CDMA and J-CDMA cellular phone systems have a very narrow channel separation and broad bandwidth. We fabricated duplexers for each system by using our unique technique, and developed low insertion loss, high attenuation and high isolation characteristics.

Keywords

capacitors; cellular radio; code division multiple access; high-pass filters; inductors; low-pass filters; mobile handsets; network synthesis; poles and zeros; surface acoustic wave resonators; CDMA cellular phone systems; SAW duplexers; SAW resonator; attenuation characteristics; broad bandwidth; circuit synthesis; external capacitor; external inductor; high-pass filter; insertion loss; isolation characteristics; low-pass filter; narrow channel separation; poles and zeros; Bandwidth; Capacitors; Cellular phones; Frequency; Inductors; Insertion loss; Multiaccess communication; Phase shifters; Poles and zeros; Surface acoustic waves;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium, 2004 IEEE

ISSN

1051-0117

Print_ISBN

0-7803-8412-1

Type

conf

DOI

10.1109/ULTSYM.2004.1417920

Filename

1417920