High-frequency amplifier with automatic neutrodyning circuit
US4910476A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 14, 1988 |
| Grant date | Mar 20, 1990 |
| Priority date | — |
| Expiry date | Oct 14, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F1/16
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
High frequency amplifiers require neutrodyning to prevent the risks of self-oscillation generated by the existence of stray capacitances among the electrodes of the active component used in the amplifier. Grid tube amplifiers (such as triodes, tetrodes, pentodes etc.) are more particularly concerned. Instead of simply providing a variable inductive element, in parallel, on the stray capacitance between the input electrode and the output electrode, there is provided a star connection of three reactances between the input electrode, the output electrode and the reference electrode. Only the first reactance is variable. The others are fixed and are in a constant ratio independent of the frequency. Preferably, the variable reactance element is an inductive element, and the other two are capacitive elements. Thus, by means of this single, variable reactance element, it is possible to make a setting, at the same time, of the input or output frequency tuning of the amplifier and of the neutrodyning.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.