Rf power amplifier with increased efficiency at low power
US5568094A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 1994 |
| Grant date | Oct 22, 1996 |
| Priority date | — |
| Expiry date | Dec 15, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/516
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An apparatus and method is provided that uses a simple voltage ratio technique to supply specific voltages to a voltage variable attenuator, and the gates of a GaAs RF power amplifier in order to control the efficiency of the amplifier. The output of the power amplifier is sampled and then fed back to the variable voltage attenuator as a control signal. A ratio portion of the control signal is then used to control the gate biases of the power amplifier. When the power requirements are less than maximum, the voltage ratio will become more negative, resulting in less current. As the RF output increases, the voltage ratio will become more positive. Therefore, as the DC voltage varies, the power amplifier's output power will vary accordingly providing the desired output power with enhanced efficiency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.