Active filter resonator and system and negative resistance generator usable therein
US5451915A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 26, 1993 |
| Grant date | Sep 19, 1995 |
| Priority date | — |
| Expiry date | May 26, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B2201/036
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A negative resistance generator includes first and second terminals; first and second inductors connected in series between the terminals; and a semiconductor amplifying device having a first control electrode connected to the first terminal and a first active electrode connected to the second terminal and a second active electrode connected to the junction of the inductors. When employed in an active filter resonator a first variable capacitor is interconnected with the inductors for setting the resonant frequency of the resonator. The resonators may be combined in an active filter with a transmission line where each of the resonators is interconnected to the line by decreasing resistance from the input to the output in order to balance the rf currents to which the resonators are subjected. An improved dual loop active filter control system is achieved by using a master oscillator that employs a resonator that is matched to the active filter resonator in the filter and servoing the frequency and Q-factor controls so that the drive signals are compensated for temperature drifts, manufacturing tolerances, and other problems while a buffer amplifier is used between the master oscilla…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.