Giuliano Visintini

Modular two-dimensional analysis of SAW filters. I. Theory

An accurate simulation tool to meet the stringent requirements for broadband surface-acoustic-wave (SAW) filters is described. The primary goal was to develop a modular software tool in which first- and second-order effects can be easily modeled as separate modules providing an overall high-precision model for SAW devices. The model takes into account surface wave diffraction and refraction, quasi-two-dimensional static charge distribution, metal resistance and external load impedances. The angular spectrum of waves formalism is interpreted in such a way as to render possible the simultaneous description of all effects mentioned. A sample of the results is given for the potential distribution.<<ETX>>

Modular two-dimensional analysis of SAW filters. II. Analysis and compensation results

For pt.I see ibid vol.39, no.1, pp.61-72 (1992). Physical effects causing distortions of the transfer function of a broadband (36% fractional bandwidth) spectrum shaping filter for digital radio with 16 quadrature amplitude modulation (QAM) are analyzed separately and connected with the modular two-dimensional (2-D) model described in Part I, demonstrating the importance of every single effect. A compensation of the second-order effects is performed, yielding an agreement between simulation and measurement in amplitude and phase of more than +or-0.1 dB and +or-1 degrees all over the passband. The stopband is also predicted with high accuracy.<<ETX>>

Determination of Parameters for the Simulation of Surface Acoustic Wave Devices with Finite Elements

Surface acoustic wave (SAW) filters are widely used in the frequency range between 30 MHz up to 3 GHz due to their outstanding filter characteristics and their reproducible production at low costs. This frequency range and thus also SAW filters will become even more important with the growth of new communication techniques in the near future.