Patent · US Expired

Frequency converting apparatus for converting an RF television signal to a video signal employing low IF techniques

US4789897A · kind A · utility

35Cited by

2References

15Claims

0Family size

Assignee

Deutsche ITT Industries, GmbH · DE

Inventors

Otmar Kappeler · Denzlingen, DE
Dietmar Ehrhardt · Glückstadt, DE

Key dates

Filing date	Mar 8, 1988
Grant date	Dec 6, 1988
Priority date	—
Expiry date	Mar 8, 2008

Classification

Technology area (CPC H)Electricity
CPC primaryH03D1/24
WIPO fieldAudio-visual technology
WIPO sectorElectrical engineering

Abstract

A frequency converter circuit for television signals is disclosed which contains a tuner and a low-IF converter which converts the television signal to a low IF signal to obtain adjacent-channel selectivity with low-pass filters. The low-IF converter further includes a phase-correcting stage and an amplitude-correcting stage for the two quadrature-signal paths. By digitizing the two signal paths after the first quadrature mixing process, their amplitude and phase stability is further improved.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.