Study of the intermodulation effects on the efficiency of the RF rectifier used for energy harvesting

Abstract

In this paper the performance of the radiofrequency (RF) rectifier used for energy harvesting is studied under different cases of the input signal. A dual-band RF rectifier operating at 1.8 and 2.45 GHz is designed and compared to a 2.45 GHz single-band rectifier to investigate the effects of the intermodulation interference on the rectifier's efficiency. The single-band rectifier is studied through two cases; single 2.45 GHz source and two combined 2.45 GHz sources. The RF rectifier is simulated and the spectrum of the output is analyzed for the different cases where it is found that the dual-band rectifier is the most suffering from the intermodulation effects. The single-band rectifier is fabricated and its output is measured while a good agreement between the simulation and measurement results is achieved. Then, the output voltage and efficiency are compared for the dual-band rectifier and dual-input single-band rectifier. Obtained results show a better efficiency for the dual-input single-band rectifier than the dual-band rectifier.