Radio frequency choke and method of use
US4394631A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 29, 1981 |
| Grant date | Jul 19, 1983 |
| Priority date | — |
| Expiry date | May 29, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H7/461
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A broadband radio frequency signal are in the range between about 5 and 400 MHz and a single phase 60 Hz AC power signal are transmitted through a cable transmission line of a cable television system. Amplifiers are powered by the 60 Hz AC signal. The amplifiers are operable as repeater stations that transmit the radio frequency (RF) signal. An RF choke connected to the transmission line separates the 60 Hz AC signal from the broadband 5 to 400 MHz signal. The RF choke includes a conductor of a preselected gauge formed in a coil having a preselected number of turns wound around a ferrite coil form. A ferrite bead is in series with the coil on a selected turn of the coil. The ferrite bead displays an RF series resistance or impedance to the inductance of the coil and reduces the series resonance of the coil. A resistor is connected in parallel to a selected turn of the coil at the opposite end of the coil and functions as a shunt. The choke serves as a high impedance which is substantially flat over the selected frequency range of 5 to 400 MHz to the broadband signal and reduces losses in the amplifier signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.