Reduced phase-shift nonlinear filters
US5694077A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 26, 1996 |
| Grant date | Dec 2, 1997 |
| Priority date | — |
| Expiry date | Jun 26, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H7/0107
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A reduced phase-shift nonlinear filter includes linear filter logic 10 responsive to a filter input signal x and having a linear transfer function G(s), which provides a linear filtered signal g, zero-cross sample-and-hold logic 16 responsive to the filter input signal x and the linear filtered signal g, which provides a square wave signal n which crosses zero at the same time and in the same direction as the filter input signal x and has an amplitude proportional to the value of the linear filtered signal g at that time, complementary filter logic 20 responsive to said square wave signal n and having a complementary transfer function (1-G(s)) which provides a complementary filtered signal c, and a summer 30 which adds the complementary filtered signal and the linear filtered signal to provide a filter output signal y which exhibits less phase shift over certain frequency bands than that of the linear transfer function. If the linear transfer function has numerator and denominator polynomials of the same order, the complementary transfer function (1-G(s)) 20 may be a reduced-order transfer function.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.