Title :
High-frequency and narrow-band STW filters for cellular power amplifiers
Author :
Yatsuda, Hiromi ; Yamanouchi, Kazuhiko ; Iijima, Hiroaki ; Mineshima, Nobuhiro
Author_Institution :
Res. Inst. of Electr. Commun., Tohoku Univ., Sendai, Japan
Abstract :
Feedforward power amplifiers for cellular base stations require a narrow-band filter in GHz range. For this application, surface transverse wave (STW) filters on Quartz have been developed. In consideration of frequency stability, the STW filters were assembled by a flip-chip technique. Flip-chip assembly can be suitable for high-frequency applications because of no bonding-wires and it can also provide high frequency-stability because of no adhesive. The insertion loss of less than 4 dB and and of more than 1500 are obtained for both of an 820 MHz filter and a 1970 MHz filter. In this paper, the frequency-stability of flip-chip STW filters is investigated. Also the center frequency shift in the flip-chip assembly process is presented
Keywords :
UHF filters; UHF power amplifiers; cellular radio; feedforward; flip-chip devices; frequency stability; surface acoustic wave filters; 1970 MHz; 4 dB; 820 MHz; SiO2; cellular base station; center frequency shift; feedforward power amplifier; flip-chip assembly; frequency stability; high-frequency narrow-band STW filter; insertion loss; quartz substrate; surface transverse wave filter; Assembly; Base stations; Bonding; Frequency; Insertion loss; Narrowband; Power amplifiers; Power filters; Stability; Surface waves;
Conference_Titel :
Ultrasonics Symposium, 1998. Proceedings., 1998 IEEE
Conference_Location :
Sendai
Print_ISBN :
0-7803-4095-7
DOI :
10.1109/ULTSYM.1998.762174
