Waveform Optimization For Efficiency Improvement of Traditional RF-to-dc Rectifiers Without Input Matching Network
Résumé
This paper reports the waveform optimization, based on pulse-modulated signal, for efficiency improvement of three traditional rectifiers: series, shunt and voltage doubler rectifiers. The circuits do not contain input matching networks. The measurement results show that the optimization of the pulse waveforms, by varying the duty cycle, makes it possible to compensate for the decrease in efficiency due to the absence of a matching circuit and also to the load resistance that deviates from its optimum value. In this work, the effort of design and optimization is reported on the waveform. At -20dBm input power level, the efficiency of RF pulse signal on unoptimized series-mounted diode rectifier is 58 % higher than that of l-tone signal applied on optimized rectifier. Meanwhile, at different loads, the efficiency of RF pulse can be 3 times higher than 1-tone signal. Similar results are obtained with shunt-mounted diode and voltage doubler rectifiers.