New low-distortion band-switching techniques for SAW antenna duplexers used in ultra-wide-band cellular phone

A new low-distortion band-switching technique for a surface-acoustic-wave (SAW) antenna duplexer used in ultra-wide-band cellular-phone systems has been developed. Both a transmitter (Tx) portion and a receiver (Rx) portion of the duplexer consist of not only wide-band SAW bandpass filters (BPFs), b...

Full description

Saved in:
Bibliographic Details
Published in:IEEE transactions on microwave theory and techniques 2004-01, Vol.52 (1), p.38-45
Main Authors: Hikita, M., Sakiyama, K., Hikino, O., Kijima, M.
Format: Article
Language:English
Subjects:
Antennas
Attenuation
Band pass filters
Band saws
Cell phones
Cellular phones
Duplexers
Frequency
Noise levels
SAW filters
Surface acoustic waves
Switching circuits
Transmitters
Ultra wideband antennas
Ultra wideband technology
Ultrawideband
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A new low-distortion band-switching technique for a surface-acoustic-wave (SAW) antenna duplexer used in ultra-wide-band cellular-phone systems has been developed. Both a transmitter (Tx) portion and a receiver (Rx) portion of the duplexer consist of not only wide-band SAW bandpass filters (BPFs), but also band-rejection SAW filters (BRFs) whose rejection bands can be shifted by switching circuits. The spurious-response sensitivity caused by the third-order nonlinear distortion of the switching circuits was dramatically improved by the new above configurations, i.e., the combination of BPFs and BRFs. The developed duplexer for the 900-MHz Japanese cdmaOne system has a size of 10 /spl times/ 8 /spl times/ 2 mm. It also has frequency characteristics of equivalent transmitted/received frequency bands as wide as 38 MHz and the guard band as narrow as 17 MHz. The insertion losses in both the low and high bands of the Tx portion are less than 2 dB, and those of the Rx portion are less than 3.3 dB. The other required specifications, e.g., attenuation at harmonic frequencies, attenuation at the image frequency, etc. are also satisfied.
ISSN:0018-9480
1557-9670
DOI:10.1109/TMTT.2003.821231