Synthesis of two classes of acoustic surface-wave filter tap weights
Abstract
Techniques are presented for the synthesis of interdigital acoustic surface-wave filter tap weights so as to give transfer functions having a Chebyshev stopband attenuation characteristic with a specified minimum attenuation along with a single-peaked or a Chebyshev double-peaked passband characteristic. The techniques first give the gain zero locations and, as a result, are very flexible. Linear phase or minimum or maximum phase-shift characteristics are obtainable. The transfer function can be factored into two sets of zeros that can be realized as two separate apodized transducers which, when operated with a multistrip coupler, will give the desired overall transfer function. It is shown that the class of designs having a double-peaked passband can be realized in the form of an unapodized phase-reversal transducer in cascade with a second transducer having very smooth apodization and no phase reversals. The fact that these designs have such smooth apodization with relatively few small taps can help in obtaining precision performance.
- Publication:
-
IEEE Transactions on Microwave Theory Techniques
- Pub Date:
- January 1976
- DOI:
- 10.1109/TMTT.1976.1128757
- Bibcode:
- 1976ITMTT..24....1M
- Keywords:
-
- Digital Filters;
- Electroacoustic Transducers;
- Microwave Filters;
- Network Synthesis;
- Surface Waves;
- Frequency Response;
- Microwave Attenuation;
- Phase Shift;
- Transfer Functions;
- Electronics and Electrical Engineering