SAW IDT Research Articles

Simulation of the frequency response of the admittance and scattering parameters of an SAW IDT

The admittance and scattering parameters of the SAW transducer are important in the design of various SAW devices. The frequency response of these parameters has been computed over a wide range of frequencies using an analysis based on a modified Mason equivalent circuit of the IDT which is not restricted to the ‘crossed-field’ and ‘inline-field’ approximations. Some of these simulated results agree satisfactorily with the experimental data available and theoretical results obtained earlier following other approaches.

GHz-Range Unidirectional Low-Loss SAW Filters and Fine Lithography Technology

The frequency ranges for mobile telephone communication are now in 1 GHz and in the next stage will be in 2∼3 GHz. Various kinds of communication systems and signal processing systems also require high frequency devices, for example, the timing pick-up filter for the light wave communication must be one of 10 GHz. For these systems, low-loss and wide-band filters or temperature stable filters are required. In this paper, GHz range SAW IDT transducers and filters together with fine-lithography techniques are described.

Generalized Analysis of Microstrip-Like Transmission Lines and Coplanar Strips with Anisotropic Substrates for MIC, Electrooptic Modulator, and SAW Application

A unified variational expression is presented for the line capacitance of a general, multilayer anisotropic structure. The propagation characteristics of a variety of striplines, microstriplines, and coplanar strips, in isolated and coupled configurations, with anisotropic substrates having optical axis aligned along the axis of the substrate, are computed. The characteristics of these structures with anisotropic substrates having tilted optical axis are also studied. Using the formulas presented, the study of structures with anisotropic substrates having aligned or tilted optical axis, for various applications including MIC, electrooptic modulator, and SAW IDT, reduces to the determination of a single admittance parameter. This parameter can be obtained from the transmission-line equivalent circuit of the structure almost by inspection.

A Study of Some Methods for Compensation for Diffraction in SAW IDT Filters

A Study of Some Methods for Compensation for Diffraction in SAW IDT Filters