Ground isolation circuit for isolating a transmission line from ground interference
US5841467A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 1, 1996 |
| Grant date | Nov 24, 1998 |
| Priority date | — |
| Expiry date | Feb 1, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/102
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An isolation circuit is disclosed for isolating ground interference from a wideband transmission signal. The ground isolation circuit of the present invention is constructed using a pair of matched mixer circuits, each of which receives a carrier signal from the same oscillator circuit. The first mixer circuit also receives the baseband signal input after appropriate conditioning, and modulates the baseband signal onto the carrier signal. In the preferred embodiment, the carrier signal has a predetermined frequency which is at least two times the frequency of the baseband signal. The modulated signal (which preferably comprises an rf signal) is transmitted via an rf transmission line to the second mixer, which demodulates the rf signal to recover the baseband signal. Each port of the mixer circuits connects to an isolation transformer to insure isolation from ground interference.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.