Digital filter system
US5856934A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 1997 |
| Grant date | Jan 5, 1999 |
| Priority date | — |
| Expiry date | Mar 27, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H17/0294
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Constants {P.sub.b00i, Q.sub.b00j, . . . , P.sub.ak2i, Q.sub.ak2j, P.sub.ci, Q.sub.cj, P.sub.di, and Q.sub.dj } for calculating each of filter coefficients {a.sub.k1, a.sub.k2, b.sub.00, b.sub.k1, b.sub.k2, c and d} for a digital filter 15 by using non-linear polynomials for pass band position data x and pass band width data y are stored in a memory 13. The constants {P.sub.b00i, Q.sub.b00j, . . . , P.sub.ak2i, Q.sub.ak2j, P.sub.ci, Q.sub.cj, P.sub.di, and Q.sub.dj } are determined by using the least square method so that the sum of the square of the errors between the filter coefficients calculated by using non-liner polynomials and the filter coefficients of digital filter having known characteristics becomes the least or the minimum. A CPU 11 calculates the filter coefficients non-linearly by using the constants stored in the memory 13, and sets the results to the digital filter 15 when new pass band position data x or pass band width data y is input at knobs SC and SW.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.