Up-down frequency converter for cable T.V.
US4352209A · kind A · utility
Inventor
Key dates
| Filing date | Mar 23, 1981 |
| Grant date | Sep 28, 1982 |
| Priority date | — |
| Expiry date | Mar 23, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D7/1408
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A cable television up-down tuner includes a first frequency up conversion stage in which a first local oscillator, tunable over a wide frequency range, is coupled to a ring diode mixer having individual biasing networks in series with each diode. A combination high pass and low pass filter provides a bandwidth coupling of input signals to the mixer. An intermediate frequency amplifier couples the up converted signal to a second mixer. A fixed tuned second local oscillator down converts the intermediate frequency signal to a selected television channel frequency. The first local oscillator includes a printed circuit board transmission line resonator which is tuned by a varactor diode. The two local oscillators are positioned adjacent the corners of a quadrilateral housing and are isolated from each other by three wall-type shields.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.