Efficiency enhancement of burst mode transmitters by RF energy recovery

Modern communication standards have high peak to average power ratios (PAPR) to achieve high spectral efficiency, trading of power amplifier (PA) efficiency. In this paper a method to directly reuse the RF energy reflected from carrier bursting PAs to improve the efficiency will be introduced and compared to conventional operation with and without DC energy recovery. Efficiency enhancement utilizing DC energy recovery is limited by the rectifier and PA efficiency. Therefore a method to reuse the RF energy directly, which does not suffer from these limitations is presented. It will be shown that it is possible to maintain high efficiency in back off with this method.