Power amplifier
US5949287A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 3, 1998 |
| Grant date | Sep 7, 1999 |
| Priority date | — |
| Expiry date | Apr 3, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F1/565
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In a power amplifier including an input matching circuit; an output matching circuit; and first and second transistors receiving a gate bias and a drain bias, the transistors having the same pinch-off voltage and being connected in parallel; resistors connected to the gates of the transistors, grounding the gate of the transistors. The resistances of the resistors are set so that when the output power increases proportionally to the input power, a gate bias applied to the first transistor exceeds the pinch-off voltage to the first transistor is ON white the gate bias applied to the second transistor does not exceed the pinch-off voltage and is OFF, and when the output power does not increase proportionally to the input power, the gate bias applied to the second transistor exceeds the pinch-off voltage of the second transistor so that both of the first and second transistors are ON. The power amplifier produces constant output power levels with respect to a wide range of input power levels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.