Herein we extract all the frequency-dependent coupling-of-modes （COM） parameters, which will be used to the rapid simulation and optimal design of surface acoustic wave （SAW） devices. FEM/BEM is used to calculate ...Herein we extract all the frequency-dependent coupling-of-modes （COM） parameters, which will be used to the rapid simulation and optimal design of surface acoustic wave （SAW） devices. FEM/BEM is used to calculate the exact field distributions of forward and backward surface acoustic waves within a finite-length periodic grating at every frequency. The middle compo- nent of the grating, regarded as a periodic structure, is selected to be investigated which can satisfy the presupposition of the COM model. From these field distributions, the values of P-matrix elements of one cell are calculated. The COM parameters taken as functions of frequency are accurately obtained. Specifically, the frequency-dependent relationships of reflection coefficient and propagation velocity are obtained independently. Using the resultant COM parameters, a one-port resonator on the substrate of 128°YX-LiNbO3 is simulated and the admittance curve shows good agreement with the simulating results using FEM/BEM. These results verify the validity and accuracy of this method.展开更多
Precise extraction of coupling-of-mode (COM) parameters plays a key role in the design for modern high performance surface acoustic wave (SAW) filters. An accurate and efficient analysis of char- acteristics for SAW p...Precise extraction of coupling-of-mode (COM) parameters plays a key role in the design for modern high performance surface acoustic wave (SAW) filters. An accurate and efficient analysis of char- acteristics for SAW propagating under periodic metal gratings has been developed based on the concept of harmonic admittance and periodic Green抯 function. Some further improvement is made on the nu- merical algorithm, such as isolation of the logarithmic singularity, asymptotic simplification of periodic Green抯 function, and utilization of Chebyshev polynomials as basis functions of the charge distribution. The most important point is extraction of the phase of coupling reflection coefficient by the characteris- tics of standing wave on the edges of stopband. This approach leads to a fast, precise and full extraction of COM parameters. The results and discussions for several materials have been presented.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos. 10774073 and 11174143)
文摘Herein we extract all the frequency-dependent coupling-of-modes （COM） parameters, which will be used to the rapid simulation and optimal design of surface acoustic wave （SAW） devices. FEM/BEM is used to calculate the exact field distributions of forward and backward surface acoustic waves within a finite-length periodic grating at every frequency. The middle compo- nent of the grating, regarded as a periodic structure, is selected to be investigated which can satisfy the presupposition of the COM model. From these field distributions, the values of P-matrix elements of one cell are calculated. The COM parameters taken as functions of frequency are accurately obtained. Specifically, the frequency-dependent relationships of reflection coefficient and propagation velocity are obtained independently. Using the resultant COM parameters, a one-port resonator on the substrate of 128°YX-LiNbO3 is simulated and the admittance curve shows good agreement with the simulating results using FEM/BEM. These results verify the validity and accuracy of this method.
基金supported by National Natural Science Foundation of China(Grant Nos.10074034 and 60261003).
文摘Precise extraction of coupling-of-mode (COM) parameters plays a key role in the design for modern high performance surface acoustic wave (SAW) filters. An accurate and efficient analysis of char- acteristics for SAW propagating under periodic metal gratings has been developed based on the concept of harmonic admittance and periodic Green抯 function. Some further improvement is made on the nu- merical algorithm, such as isolation of the logarithmic singularity, asymptotic simplification of periodic Green抯 function, and utilization of Chebyshev polynomials as basis functions of the charge distribution. The most important point is extraction of the phase of coupling reflection coefficient by the characteris- tics of standing wave on the edges of stopband. This approach leads to a fast, precise and full extraction of COM parameters. The results and discussions for several materials have been presented.
