Surface Acoustic Wave Filters

With Applications to Electronic Communications and Signal Processing


  • David Morgan, Consultant, UK

This book gives the fundamental principles and device design techniques for surface acoustic wave filters. It covers the devices in widespread use today: bandpass and pulse compression filters, correlators and non-linear convolvers and resonators. The newest technologies for low bandpass filters are fully covered such as unidirectional transducers, resonators in impedance element filters, resonators in double-mode surface acoustic wave filters and transverse-coupled resonators using waveguides. The book covers the theory of acoustic wave physics, the piezoelectric effect, electrostatics at a surface, effective permittivity, piezoelectric SAW excitation and reception, and the SAW element factor. These are the main requirements for developing quasi-static theory, which gives a basis for the non-reflective transducers in transversal bandpass filters and interdigital pulse compression filters. It is also needed for the reflective transducers used in the newer devices.
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R&D electrical and electronic engineers developing electronic systems (with applications mainly in mobile communications, radar and broadcasting) using surface acoustic wave devices; academic researchers; graduate level electrical and electronic engineering students.


Book information

  • Published: June 2007
  • ISBN: 978-0-12-372537-0

Table of Contents

PrefaceForewordPrefaces and Forewords to previous books (1985, 1991)1. Basic Survey 1.1. Acoustic waves in solids 1.2. Propagation effects and materials 1.3. Basic Properties of interdigital transducers 1.4. Apodization and transversal filtering 1.5. Correlation and signal processing 1.6. Wireless interrogation - sensors and tags 1.7. Resonators and low-loss filters 1.8. Summary of devices and applications2. Acoustic waves in elastic solids 2.1. Elasticity in anisotropic materials 2.2. Waves in isotropic materials 2.3. Waves in anisotropic materials3. Electrical excitation at a plane surface 3.1. Electrostatic case 3.2. Piezoelectric half-space 3.3. Some properties of the effective permittivity 3.4. Green’s function 3.5. Other applications of the effective permittivity4. Propagation effects and materials 4.1. Diffraction and beam steering 4.2. Propagation loss and non-linear effects 4.3. Temperature effects and velocity errors 4.4. Materials for surface-wave devices5. Non-reflective transducers 5.1. Analysis for a general array of electrodes 5.2. Quasi-static analysis of transducers 5.3. Summary and P-matrix formulation 5.4. Transducers with regular electrodes - element factor 5.5. Admittance of uniform transducers 5.6. Two-transducer devices6. Bandpass filtering using non-reflective transducers 6.1. Basic properties of uniform transducers 6.2. Apodised transducer as a transversal filter 6.3. Design of transversal filters 6.4. Filter design and performance7. Correlators for pulse compression radar and communications 7.1. Pulse compression radar 7.2. Chirp waveforms 7.3. Interdigital chirp transducers and filters 7.4. Reflective array compressors 7.5. Doppler effects and spectral analysis 7.6. Correlation in spread-spectrum communications 8. Reflective gratings and transducers 8.1. Reflective array method for gratings and transducers 8.2. Coupling-of-modes (COM) equations 8.3. Numerical evaluation of COM parameters9. Unidirectional transducers and their application to bandpass filtering 9.1. General considerations 9.2. DART mechanism and analysis 9.3. Bandpass filtering using DART’s 9.4. Other SPUDT structures and analysis for parameters 9.5. Other SPUDT filters 9.6. Other low-loss techniques10. Waveguides and transversely-coupled resonator (TCR) filters 10.1. Basic strip waveguides 10.2. Waveguide modes in interdigital devices 10.3. Analysis for general waveguides 10.4. Transversely-coupled resonator (TCR) filter 10.5. Unbound waveguide modes 10.6. Waveguides including electrode reflectivity11. Resonators and resonator filters 11.1. Resonator types 11.2. Surface-wave oscillators 11.3. Impedance element filters using resonators 11.4. Leaky waves 11.5. Longitudinally-coupled resonator (LCR) filters`Appendix A. Fourier transforms and linear filters A.1. Fourier transforms A.2. Linear filters A.3. Matched filtering A.4. Non-uniform sampling A.5. Some properties of bandpass waveforms A.6. Hilbert transformsAppendix B. Reciprocity B.1. General relation for a mechanically free surface B.2. Reciprocity for two-terminal transducers B.3. Symmetry of the Green’s function B.4. Reciprocity for surface excitation of a half-space B.5. Reciprocity for surface-wave transducers B.6. Surface wave generationAppendix C. Elemental charge density for regular electrodes C.1. Some properties of Legendre functions C.2. Elemental charge density C.3. Net charges on electrodesAppendix D. P-matrix relations D.1. General relations D.2. Cascading formulaeAppendix E. Electrical loading in an array of regular electrodes E.1. General solution for low frequencies E.2. Propagation outside the stop band E.3. Stop bands E.4. Theory of the multistrip coupler