Shunichi Seki
Panasonic
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Publication
Featured researches published by Shunichi Seki.
internaltional ultrasonics symposium | 1997
Keiji Onishi; Akihiko Namba; Hiroki Sato; Tetsuyosi Ogura; Shunichi Seki; Yutaka Taguchi; Yosihiro Tomita; Osamu Kawasaki; Kazuo Eda
We have developed a novel temperature compensation method for SAW devices using a direct bonding technique. The SAW device applied this method was composed of a conventional piezoelectric substrate such as LiTaO/sub 3/ and LiNbO/sub 3/, directly bonded without any bonding agents to a glass substrate having a relatively low thermal expansion coefficient (TEC). The piezoelectric substrate and the glass substrate were bonded in an atomic scale and the interface was very uniform. Therefore, the thermal strain at the surface of the bonded substrate caused by the difference between the TECs of the substrates was quite uniform and stable. With this structure, the thermal expansion of the piezoelectric substrate was restrained and the elastic constant of the piezoelectric substrate was changed by the thermal strain. Using this technique, we have succeeded to improve the temperature coefficient of frequency (TCF) of the SAW devices without causing any deterioration in the frequency response. This novel temperature compensation method is very promising for RF-SAW device applications.
international microwave symposium | 1996
Yutaka Taguchi; Shunichi Seki; Keiji Onishi; Kazuo Eda
A new balanced-unbalanced type RF-band (950 MHz) surface acoustic wave (SAW) filter for use in portable telephones is presented. This SAW filter has unbalanced input and balanced output terminals. Balanced-unbalanced type SAW filters having a pass-band at 950 MHz were fabricated. The obtained results showed excellent characteristics such as low insertion loss, wide bandwidth, and small VSWR. Using the SAW filter, one can realize balanced-type RF circuits in portable telephones.
international microwave symposium | 1995
Yutaka Taguchi; Shunichi Seki; Keiji Onishi; Kazuo Eda
A new balanced-type RF-band (950 MHz) surface acoustic wave (SAW) filter using SAW resonators for use in portable telephones is presented. This SAW filter has balanced input and output terminals. Based on the computer simulation, balanced-type SAW filters having a pass-band at 950 MHz were fabricated. The obtained characteristics showed excellent characteristics such as low insertion loss, wide bandwidth, high attenuation at stopbands, and small VSWR. Using the SAW filter, one can realize balanced-type RF circuits in portable telephones.<<ETX>>
Archive | 1994
Keiji Onishi; Shunichi Seki; Yutaka Taguchi; Kazuo Eda
Archive | 1977
Shunichi Seki; Kazuo Eda; Yutaka Taguchi; Keiji Onishi
Archive | 1997
Keiji Onishi; Hideki Iwaki; Shunichi Seki; Yutaka Taguchi; Tsukasa Shiraishi; Yoshihiro Bessho; Osamu Kawasaki; Kazuo Eda
Archive | 1994
Kazuo Eda; Yutaka Taguchi; Keiji Onishi; Shunichi Seki
Archive | 1998
Keiji Onishi; Shunichi Seki; Yutaka Taguchi; Kazuo Eda
Archive | 1998
Yutaka Taguchi; Kazuo Eda; Osamu Kawasaki; Yosihiro Tomita; Keiji Onishi; Shunichi Seki; Akihiko Namba; Hiroki Sato; Tetsuyosi Ogura
Archive | 1996
Keiji Onishi; Shunichi Seki; Yutaka Taguchi; Kazuo Eda
