Toshiyuki Fuyutsume
Murata Manufacturing
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Publication
Featured researches published by Toshiyuki Fuyutsume.
internaltional ultrasonics symposium | 2016
Tsutomu Takai; Yuichi Takamine; Hisashi Yamazaki; Toshiyuki Fuyutsume; Haruki Kyoya; Takeshi Nakao; Hajime Kando; Masahiro Hiramoto; Takanori Toi; Masayoshi Koshino; Norio Nakajima
High Q and low TCF are elemental characteristics for SAW resonator, in order to realize high performance filters and duplexers coping with new LTE frequency bands. Authors focus on the acoustic energy confinement in SAW propagation surface and electrical characteristics have been investigated theoretically and experimentally. A new multi-layered structure substrate have realized incredible high performances such as both three times Q and one fifth TCF compared with conventional structure. Band25 duplexer using the new structure has been developed successfully with low loss and good temperature stability.
IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control | 2017
Tsutomu Takai; Yuichi Takamine; Hisashi Yamazaki; Toshiyuki Fuyutsume; Haruki Kyoya; Takeshi Nakao; Hajime Kando; Masahiro Hiramoto; Takanori Toi; Masayoshi Koshino; Norio Nakajima
To develop the high-performance filters and duplexers required for recent long-term evolution frequency bands in mobile handsets, a surface acoustic wave (SAW) resonator is needed that has a higher quality (Q) and a lower temperature coefficient of frequency (TCF). To achieve this, the authors focused on acoustic energy confinement in the depth direction for a rotated Y-X LiTaO3 (LT) substrate. Characteristics of multilayered substrates with low-impedance and high-impedance layers under LT layer were studied numerically in terms of acoustic energy distribution, phase velocity, coupling coefficient, and temperature characteristics employing a finite-element method simulation. After several calculations, a novel multilayered structure was developed that uses SiO2 for a low-impedance layer and AlN for a high-impedance layer under the thin LT layer. A one-port resonator using the new substrate was fabricated, and its experimental results showed that the developed resonator had a Bode-Q over 4000 and TCF of −8 ppm/°C, which are four times higher than and one-fifth as small as those of a conventional 4° YX-LT SAW resonator, respectively. By applying this technology, a band 25 duplexer with very narrow duplex gap was successfully developed, which shows extremely low insertion loss, steep cutoff characteristics, and stable temperature characteristics.
internaltional ultrasonics symposium | 2017
Tsutomu Takai; Yuichi Takamine; Toshiyuki Fuyutsume; Takeshi Nakao; Masahiro Hiramoto; Takanori Toi; Masayoshi Koshino
Various characteristics for RF filters in mobile terminals are required corresponding to expansion of mobile terminals. I.H.P. SAW (Incredible High-performance SAW) with high Q and temperature stability has been developed to resolve these challenges. In this paper, its high Q mechanism of the new multi-layered structure (LiTaO3 / SiO2 / AlN / Si substrate) has been studied numerically in terms of acoustic energy confinement by using wave propagation analysis in real-space and wavenumber domains. One-port resonators employing I.H.P. SAW were fabricated after optimizing the multi-layered structure. Experimental results show higher Bode-Q values over 6000 at 0.9 GHz to 1900 at 3.5GHz successfully, which are over 3 times higher than those of conventional 42YX-LT SAW resonators. Very small TCF of −8 ppm/°C is also realized, and wider bandwidth and superior heat dissipation performance have been achieved. A new Wi-Fi filter with very narrow adjacent gaps and a new Band 25 / 66 / 30 hexaplexer, one of the most difficult multiplexers, have been developed using I.H.P. SAW technology, which show low insertion loss, steep cut-off, deep attenuation and extremely high isolation characteristics.
Archive | 2009
Hajime Kando; Naohiro Nodake; Masahiko Saeki; Toshiyuki Fuyutsume
Archive | 2007
Hajime Kando; Naohiro Nodake; Masahiko Saeki; Toshiyuki Fuyutsume
Archive | 2002
Kenji Sakaguchi; Toshiyuki Fuyutsume
Archive | 2008
Toshiyuki Fuyutsume; Taro Nishino; Hisashi Yamazaki; Noboru Tamura; Nakaba Ichikawa; Masaki Aruga
Archive | 2002
Kenji Sakaguchi; Toshiyuki Fuyutsume; Yoshihiro Koshido
Archive | 2008
Daisuke Yamamoto; Hajime Kando; Akihiro Teramoto; Toshiyuki Fuyutsume; Masahiko Saeki
Archive | 2009
Shin Saijou; Toshiyuki Fuyutsume