Optimum, multiple signal path, multiple-mode filters and method for making same
US5576674A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 17, 1995 |
| Grant date | Nov 19, 1996 |
| Priority date | — |
| Expiry date | Mar 17, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01P1/2086
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A preferred realization of a frequency spectrum filter incorporating multiple signal paths is selected using a new design tool, a plot of resonator coupling coefficient values representing filter designs having equivalent signal transfer characteristics. The design plot is formed by first subjecting an initial matrix of resonator coupling coefficients, representing a particular filter design, to pre-multiplications by selected plane rotation matrices--which each have their respective rotation angles--and to post-multiplications by their transposes. Equations for the individual elements that form the resulting modified coupling coefficient matrix are then plotted over a range of one of the rotation angles. Examination of the result plot leads to a selection of a set of coupling values in observance of predetermined criteria. An optimum realization of the filter is then constructed by adjusting the physical resonator couplings so that they conform to the coupling values selected from the plot. Some preferred realizations of dual-mode bandpass filters, which have been designed using this technique, are described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.