Title :
A SAW shaping filter for high data rate MSK-encoding in a broadband DS-CDMA system
Author :
Zenzinger, A. ; Morhart, F. ; Reindl, L. ; Weigel, R.
Author_Institution :
Lehrstuhl fur Hochfrequenztech., Tech. Univ. Munchen, Germany
Abstract :
We report on two surface acoustic wave (SAW) shaping filters which generate a minimum shift keying (MSK) modulated signal by converting a BPSK modulated signal. The filters are intended to be used for modulators with high data rates, as it is necessary in broadband direct sequence code division multiple access (DS-CDMA) systems. One filter has been fabricated from a lithium tantalate (LiTaO/sub 3/) substrate, and one from a quartz substrate. The filter on LiTaO/sub 3/ fulfills all requirements dealing with spectrum shaping. However, the temperature range is not as wide as with quartz substrates due to the higher temperature coefficient of LiTaO/sub 3/. The filter on quartz is very stable from the temperature coefficient point of view, but the insertion attenuation and spurious electromagnetic feedthrough are relatively high.
Keywords :
UHF filters; broadband networks; code division multiple access; digital radio; minimum shift keying; modulation coding; modulators; phase shift keying; pseudonoise codes; spread spectrum communication; surface acoustic wave filters; 2.45 GHz; BPSK modulated signal; LiTaO/sub 3/; MSK modulated signal; SAW shaping filters; UHF; broadband DS-CDMA system; digital communication system; direct sequence code division multiple access; high data rate MSK-encoding; indoor radio; insertion attenuation; lithium tantalate substrate; minimum shift keying; modulators; quartz substrate; spectrum shaping; spurious electromagnetic feedthrough; temperature coefficient; temperature range; Acoustic waves; Binary phase shift keying; Direct-sequence code-division multiple access; Filters; Lithium compounds; Modulation coding; Multiaccess communication; Signal generators; Surface acoustic waves; Temperature distribution;
Conference_Titel :
Wireless Applications Digest, 1997., IEEE MTT-S Symposium on Technologies for
Conference_Location :
Vancouver, BC, Canada
Print_ISBN :
0-7803-3318-7
DOI :
10.1109/MTTTWA.1997.595128
