Analysis of the film thickness dependence of a single-phase unidirectional transducer using the coupling-of-modes theory and the finite-element method

Chen, Z.H.; Takeuchi, Masao; Yamanouchi, Kaoru

doi:10.1109/58.166814

Cited by 31 publications

(7 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5 to 7. The value of the phase 0, of the intermodal coupling coefficient agrees well with the results by the perturbation method [2]. This phase variation is rather gradual with respect to that of the film thickness and has design advantages.…”

Section: Numerical Examplessupporting

confidence: 86%

A solution method based on the coupled‐mode theory for natural single‐phase unidirectional surface acoustic wave transducers

Hasegawa

Inagawa

Koshiba

1994

Electron Comm Jpn Pt II

View full text Add to dashboard Cite

A method for analysis of natural single‐phase unidirectional transducer (NSPUDT), which is one of unidirectional surface acoustic wave interdigital electrodes, is proposed in which the mode coupling theory and the finite‐element method are used. the finite‐element method is used for calculations of the upper and lower limit frequencies of the stop band, the potential standing wave distribution at these frequencies, and the static capacitance per electrode pair for the short and open gratings corresponding to the electric terminals either shorted or open. In the substrate used for NSPUDT, the locations of the maximum and minimum of the standing wave in general vary in the depth direction of the substrate. Hence, it is not possible to use the standing wave pattern in the substrate as is used for a substrate surface where electrodes are present. the variation of the potential in the depth directional of the substrate is incorporated into the mode coupling theory in this research, so that the depth dependence of the standing wave profile is qualitatively evaluated. Hence, it is made possible to confirm the locations of the maximum and minimum of the standing wave at the substrate surface from the standing wave profile in the substrate. Specifically, the present method is applied to NSPUDT on an ST‐cut 25deg; X‐propagation quartz substrate so that its validity and usefulness are confirmed.

show abstract

Section: Numerical Examplessupporting

confidence: 86%

A solution method based on the coupled‐mode theory for natural single‐phase unidirectional surface acoustic wave transducers

Hasegawa

Inagawa

Koshiba

1994

Electron Comm Jpn Pt II

View full text Add to dashboard Cite

show abstract

“…According to Kirchhoff' s law, the following two equations are derived for right and left closed loops: Then, the directivity D defined as the ratio of power consumption at the right and left 2; is given by Equation (16) is identical to (27) in [12]. The derivation procedure using the equivalent circuit is simple and allows understanding of the directional behaviors.…”

Section: Discussionmentioning

confidence: 99%

Equivalent circuits for unidirectional SAW-IDTs based on the coupling-of-modes theory

Nakamura

Hirota

1996

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

View full text Add to dashboard Cite

Abstruct-A three-port distributed-parameter equivalent circuit representing the whole structure of a unidirectional interdigital transducer (IDT) is derived from generalized coupling-ofmodes (COM) equations with complex parameters. The circuit has a simple form similar to that of a bidirectional IDT, but involves two additional impedance elements of opposite signs. It is shown that the two additional elements well express the behaviors of unidirectional IDT's and the directivity can easily he derived from the equivalent circuit. Some examples of calculations of device characteristics using the circuit are also presented.

show abstract

“…Similar development of the finite element model for the analysis of piezoelectric devices has also been presented previously (Lerch, 1990). The model differs from other finite element modeling of SAW devices (e.g., Hasegawa and Koshiba, 1990;Chen, et al, 1992) in that it aims to conduct full scale simulation of electromechanical phenomena in SAW devices with minimum restrictions.…”

Section: Finite Element Formulationmentioning

confidence: 97%

A Finite Element Analysis of Second Order Effects on the Frequency Response of a SAW Device

Jiang

2001

Journal of Intelligent Material Systems and Structures

View full text Add to dashboard Cite

Electrode perturbation of the surface may cause significant second order effects on the frequency response of surface acoustic wave (SAW) devices for high frequency applications. These effects in a Y-Z lithium niobate filter are analyzed using a recently developed finite element model. In this model, the equations of wave propagation in piezoelectric materials are discretized using the Galerkin method, in which an implicit algorithm of the Newmark family with unconditional stability is implemented. The Rayleigh damping coefficients are included in the elements near the boundary to reduce the interference of reflected waves. The frequency response of the filter is obtained through the Fourier transform of the impulse response, which is solved directly from the finite element simulation. The analyses have shown that for aluminum electrodes of fixed thickness, the second order effects on the frequency response become increasingly significant as the device is scaled smaller to have higher central frequencies. Typically, for aluminum electrodes of thickness 2000 Å, the frequency response is significantly distorted for the device of the central frequency at above 2 GHz. Quantitative analyses of the second order effects in the device of various center frequencies provide insights for designing high performance SAW devices for high frequency applications.

show abstract

Analysis of the film thickness dependence of a single-phase unidirectional transducer using the coupling-of-modes theory and the finite-element method

Cited by 31 publications

References 21 publications

A solution method based on the coupled‐mode theory for natural single‐phase unidirectional surface acoustic wave transducers

A solution method based on the coupled‐mode theory for natural single‐phase unidirectional surface acoustic wave transducers

Equivalent circuits for unidirectional SAW-IDTs based on the coupling-of-modes theory

A Finite Element Analysis of Second Order Effects on the Frequency Response of a SAW Device

Contact Info

Product

Resources

About