Surface Acoustic Wave (surface + acoustic_wave)

Distribution by Scientific Domains


Selected Abstracts


Robust optimum design of SAW filters by the penalty function method

ELECTRICAL ENGINEERING IN JAPAN, Issue 3 2007
Kiyoharu Tagawa
Abstract In order to increase the reliability of surface acoustic wave (SAW) filters, a robust optimum design technique is presented. The frequency response characteristics of SAW filters are governed primarily by their geometrical structures, that is, the configurations of the interdigital transducers (IDTs) and reflectors fabricated on piezoelectric substrates. To choose desirable structures of SAW filters through computer simulation, conventional design techniques utilize the equivalent circuit model of the IDT. However, they have rarely considered the accuracy of the underlying model, which may be degraded by the dispersion of the circuit parameters. In this paper, considering the errors of these parameters, the robust optimum design of SAW filters is formulated as a constrained optimization problem. Then, a penalty function method combined with an improved variable neighborhood search is proposed and applied to the problem. Computational experiments conducted on a practical design problem of a resonator type SAW filter demonstrate the usefulness of the proposed method. 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 158(3): 45,54, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20469 [source]


Progress in SWNT based, SAW driven charge pumps

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 13 2006
Viktor Siegle
Abstract The work presented gives a short overview of existing implementations for single electron pumps. A proposal by Talyanskii et al. [Phys. Rev. Lett. 87, 276802 (2001)] for a single walled carbon nanotube (SWNT) based device is discussed. SWNT is suggested to function as one-dimensional channel for electrons, which are driven by the surface acoustic wave (SAW). The SAW is created on the surface of a piezoelectric by lithographically defined structures. This work addresses the details in manufacturing such a device. This work investigates the possibilities of growing SWNTs by chemical vapor deposition (CVD) on the surface of LiNbO3, which is known for its excellent piezoelectric properties. The results of this study are reported together with the progress in fabrication of such a device. ( 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Coherent spin transport by acoustic fields in GaAs quantum wells

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2006
O. D. D. Couto
Abstract We review processes for long-range spin transport and manipulation in GaAs quantum wells using mobile potentials created by the piezoelectric field of a surface acoustic wave. By reducing spin dephasing mechanisms associated with the spin orbit-coupling, these potentials can coherently transport spins over distances on the order of 100 m. ( 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Fabrication and properties of InSb films with ion-beam sputtering for use in the amplification of magneto-surface-acoustic waves

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 8 2004
N. Obata
Abstract The magnetic surface acoustic wave (MSAW) device can be manipulated by an external magnetic field. However the MSAW is attenuated largely at high frequencies above MHz. Therefore, we proposed a MSAW device having a hybrid structure consisting of FeB amorphous thin film/InSb semiconductor thin film/LiNbO3 substrate. This device is utilized for amplification of surface acoustic waves by the interaction between surface acoustic waves and the carriers in the InSb semiconductor. We prepared (111) InSb thin films by ion beam sputtering. We obtained InSb thin films having Hall mobilities of about 2000 cm2/Vs by subsequent annealing. This showed the possibility of MSAW amplification by low voltages. ( 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]