Efficient design tool for SAW-resonator filters

The advantages of the coupling-of-modes (COM) formalism and the transmission-matrix approach are combined to create exact and computationally efficient analysis and synthesis CAD tools for the design of SAW-resonator filters. The models for the filter components, especially gratings, interdigital transducers (IDTs). and multistrip couplers (MSCs), are based on the COM approach, which delivers closed-form expressions. In order to determine the relevant COM parameters, the integrated COM differential equations are compared with analytically derived expressions from the transmission-matrix approach. The most important second-order effects such as energy storage, propagation loss and mechanical and electrical loading are fully taken into account. As an example, the authors investigate a two-pole, acoustically coupled resonator filter at 914.5 MHz on AT quartz. Excellent agreement between theory and measurement is found.<<ETX>>

[1]  P. Cross.  Properties of Reflective Arrays for Surface Acoustic Resonators , 1976, IEEE Transactions on Sonics and Ultrasonics.

[2]  J. J. Gagnepain,et al.  Rayleigh Wave Resonators and Oscillators , 1985 .

[3]  H. A. Haus,et al.  The Analysis of Grating Structures by Coupling-Of-Modes Theory , 1980 .

[4]  K. A. Ingebrigtsen.  A Normal Mode Representation of Surface Wave Multistrip Couplers , 1973 .

[5]  D. P. Morgan,et al.  Quasi-Static Analysis of Generalized SAW Transducers Using the Green's Function Method , 1980, IEEE Transactions on Sonics and Ultrasonics.

[6]  S. Datta,et al.  Element Factor for Periodic Transducers , 1980, IEEE Transactions on Sonics and Ultrasonics.

[7]  R. Collin.  Foundations for microwave engineering , 1966 .

[8]  P. Zibis,et al.  UHF Low Loss SAW Filters for Front End Applications , 1986, IEEE 1986 Ultrasonics Symposium.

[9]  Edward Martin Garber.  Surface acoustic wave single-phase unidirectional transducers and phase weighting , 1985 .

[10]  G. Tobolka,et al.  Mixed Matrix Representation of SAW Transducers , 1979, IEEE Transactions on Sonics and Ultrasonics.

[11]  G. Coquin,et al.  Filters and Dispersive Delay Lines Using Repetitively Mismatched Ultrasonic Transmission Lines , 1968, IEEE Transactions on Sonics and Ultrasonics.

[12]  R.C.M. Li,et al.  The Influence of Stored Energy at Step Discontinuities on the Behavior of Surface-Wave Gratings , 1975, IEEE Transactions on Sonics and Ultrasonics.

[13]  H. Haus,et al.  Analysis of Metal-Strip SAW Gratings and Transducers , 1985, IEEE Transactions on Sonics and Ultrasonics.

[14]  P. V. Wright,et al.  Modeling and Experimental Measurements of the Reflection Properties of SAW Metallic Gratings , 1984 .

[15]  R. Weigel,et al.  Accurate prediction of dispersion and attenuation of long metal strip SAW waveguides on anisotropic substrate , 1988, IEEE 1988 Ultrasonics Symposium Proceedings..