High-frequency and narrow-band STW filters for cellular power amplifiers
説明
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.
収録刊行物
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- 1998 IEEE Ultrasonics Symposium. Proceedings (Cat. No. 98CH36102)
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1998 IEEE Ultrasonics Symposium. Proceedings (Cat. No. 98CH36102) 1 403-406, 2002-11-27
IEEE