Radio frequency power amplifier and communication system
US7098740B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 2003 |
| Grant date | Aug 29, 2006 |
| Priority date | — |
| Expiry date | Oct 21, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/21178
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
There is provided not only a radio frequency power amplifier using an SiGe HBT subject to a little amplification distortion, but also a communication system using the same. A conventional radio frequency power amplifier provides base bias paths of transistors Q1 through QN (SiGe HBT) with bias resistors R11 through R1N having resistance values three to five times higher than those of a ballast resistor attached to each transistor's base. A coil LB is provided in parallel with the bias resistor as a means for compensating a voltage drop due to direct current component IDC flowing through the bias resistor. Addition of the bias resistor suppresses non-linearity of low-frequency variations in an output current. Addition of the coil compensates for voltage drop. Accordingly, the maximum linear output power can be improved. As a result, it is possible to provide the power amplifier subject to a little amplification distortion within a wide output range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.