A. Khanifar, R. Braithwaite | 2012 |
Download original file. Abstract — A high efficiency feedforward power amplifier (FFPA) is proposed that uses the Doherty configuration for both the main amplifier (MA) and error amplifier (EA). Using a nonlinear EA is a deviation from the traditional FFPA. A loop control algorithm is proposed that offsets the alignment setting from the standard value to best utilize the power handling capability and linearity of the MA and EA. A system efficiency of 25% is achieved for a rated power of 52.7 dBm, while exceeding the WCDMA specifications. Reducing the peak-to-average power ratio (PAPR) of the input signal to 8 dB and using offset control improves the ACLR performance to -62 dBc.
Conclusion
A feedforward power amplifier with a rated power of 52.7 dBm uses a nonlinear error amplifier to increase system efficiency to 25%. Crest factor reduction and offset alignment control improve the ACLR performance to -62 dBc.
A feedforward power amplifier with a rated power of 52.7 dBm uses a nonlinear error amplifier to increase system efficiency to 25%. Crest factor reduction and offset alignment control improve the ACLR performance to -62 dBc.
