DESIGN OF MICROWAVE FILTER NETWORKS.
Abstract
The frequency transformation W = 1/S, where S = j tan theta, is investigated for commensurate transmission-line networks consisting of stubs, resistors, ideal transformers, and unit elements. This transformation takes transmission-line transformers into transmission-line low-pass filters and vice versa, low-pass (or bandstop) filters into high-pass (or bandpass) filters and vice versa, and elliptic-function bandstop filters into elliptic-function bandpass filters and vice versa. The practicality of the transformation lies in the fact that element values of the transformed network are easily related to the corresponding element values of the original network. Several examples of designs using the transformation are given, one of which is the design of an unusual narrow-band 3-dB directional coupler. An equivalent circuit for piezoelectric transducers for converting microwave electromagnetic energy to acoustic energy is derived. This circuit is similar to Mason's except that Mason's circuit was for lower frequency applications. With the aid of this equivalent circuit it is possible to analyze a microwave acoustic transducer in much the same way that an ordinary microwave coupling network would be analyzed. By means of design techniques analogous to those now well established for the design of microwave coupling networks and filters, it may be possible to derive criteria for optimum design of microwave acoustic transducers. A computer program has been prepared for the analysis of transducers using acoustic step transformers for matching on the acoustic side of the transducer, and electrical filter networks for matching on the electrical side of the transducer.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1966
- Accession Number
- AD0803993
Entities
People
- E. G. Cristal
- G. L. Matthaei
- Leo Young
Organizations
- SRI International