Title :
A low loss CDMA-IF filter based on RSPUDT on LBO substrate
Author :
Ichikawa, Shuichi ; Mitobe, S. ; Koshino, Masayoshi ; Ebata, Y.
Author_Institution :
SAW Eng. Dept., Toshiba Corp., Yokohama, Japan
Abstract :
A high performance and novel SAW IF 210 MHz filter for CDMA (PCS) system is developed on LBO substrate. The filter consists of double-tracked filters which are connected in parallel on one chip. The main track-filter is RSPUDT filter having grating reflectors, and mainly performs low loss pass-band of the total filter. The sub-track filter consists of SPUDTs arranged either side of grating reflectors. It is set to be phase-inversion at the cutoff frequency region to improve the skirt slope of the main-track filter, but is suppressed at the pass-band to avoid degrading the insertion loss of main-track filter. The minimum insertion loss of 3.5 dB, the phase linearity of 3.3° rms and the stop band attenuation better than 35 dB are achieved successfully. The developed IF filter fits into small sized ceramic package (7.0×5.0×1.6 mm3) and has high performances of the frequency characteristics.
Keywords :
code division multiple access; lithium compounds; mobile radio; surface acoustic wave filters; telephone sets; 210 MHz; 3.5 dB; CDMA PCS system; LBO substrate; Li2B4O7; RSPUDT; SAW IF filter; ceramic package; double tracked filter; insertion loss; mobile phone; Attenuation; Band pass filters; Cutoff frequency; Degradation; Gratings; Insertion loss; Linearity; Multiaccess communication; Personal communication networks; Surface acoustic waves;
Conference_Titel :
Ultrasonics Symposium, 1999. Proceedings. 1999 IEEE
Conference_Location :
Caesars Tahoe, NV
Print_ISBN :
0-7803-5722-1
DOI :
10.1109/ULTSYM.1999.849417
