Very small-sized resonator filter using shear horizontal wave on quartz

M. Kadota, T. Yoneda, K. Fujimoto, T. Nakao, E. Takata

研究成果: Article査読

28 被引用数 (Scopus)


By composing interdigital transducers (IDTs) and reflectors consisting of films made of a heavy metal such as Au, Ta or W on an ST cut 90°X propagation (direction perpendicular to X-axis) quartz substrate, the authors realized a new type of shear horizontal (SH) wave. This wave has an excellent temperature characteristic, a large electromechanical coupling factor (k), and a large reflection coefficient at reflector electrodes. The square of this electromechanical coupling factor (k2 = 0.28 ∼ 0.34%) and the reflection coefficient at reflector electrodes are 2.2 ∼ 2.6 times and 30 ∼ 35 times, respectively, as large as those of a Rayleigh wave on an ST cut X propagation quartz substrate. The authors applied this technology to filters for the first intermediate frequency (first IF) stage of a global system for mobile communications (GSM) in the nominal center frequency from 200 to 400 MHz. As a result, we succeeded in developing the first IF filter having a low insertion loss, an excellent temperature characteristic (frequency shift: 1 ppm/°C) and a small package size (3 × 3 mm2), which is as small as a radio frequency (RF) surface acoustic wave (SAW) filter, for the first time.

ジャーナルJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
5 B
出版ステータスPublished - 2001 5 1

ASJC Scopus subject areas

  • 工学(全般)
  • 物理学および天文学(全般)


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