An Efficiency Improved Balanced Power Amplifier Using Power- Recycling Technique
Date Issued
2011
Date
2011
Author(s)
Chang, Chun-Wei
Abstract
In general, the power amplifier ( PA ) is one of the most power-hungry devices in a wireless transceiver. Therefore, the longer the mobile devices can operate when the higher the PA efficiency. Linearity and efficiency are two key parameters to determine the performance of wireless transmitters, so linearity and efficiency must be traded-off in the PA. That is, we got more efficiency while the linearity is decreased. This thesis is a method for improving the efficiency of a balanced PA under load mismatch by recycling the reflected power. The reflected power will be directed to the isolated port of a 90° hybrid coupler. The reflected power can then by rectified and converted back to dc power to assist in supplying the PA. A prototype system was built to validate the concept and tested under various phase angles with 2:1 and 4:1 VSWR using a W-CDMA voice signal at 836.5 MHz.
Measurement results show that the power recycling technique improves the overall efficiency by as much as 14.7% and 22.1 % when 2:1 and 4:1 VSWR of the output power level is 25 dBm. The proposed an efficiency improved balanced PA using power recycling technique, we believe our designs are valid and effective directions to achieve improving the efficiency of PAs.
Subjects
Power amplifiers
Radio transceiver
Power- Recycling technique
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-100-R99525091-1.pdf
Size
23.54 KB
Format
Adobe PDF
Checksum
(MD5):6d1691e0e30ee52f6636904e6d30efc4