Phasing receivers
US6278870A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1998 |
| Grant date | Aug 21, 2001 |
| Priority date | — |
| Expiry date | Sep 23, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D2200/0017
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A phasing receiver includes a quadrature mixing arrangement for frequency converting an input or high IF information signal to a pair of quadrature related low IF signals. The low IF signals are applied to a polyphase filter which functions as a low pass and adjacent channel rejection filter. One or more elements effecting a fine adjustment of relative phase away from quadrature and/or relative amplitude away from equality of the low IF signals are incorporated in information or oscillator signal paths in or about the mixing arrangement or a superhet stage preceding the quadrature mixing arrangement. These elements effect a predistortion of relative phase and/or relative amplitude of the low IF signals in order to compensate for mismatches in an input stage of the filter, and thereby improve image rejection by the filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.