Dual Circularly Polarized Ultrawideband Rectenna with High Efficiency for Wireless Energy Harvesting

This paper presents an ultrawideband dual circularly polarized (CP) rectenna for wireless energy harvesting (WEH) applications. It is mainly composed of a dual CP antenna and an ultrawideband rectifier. The receiving antenna is fed by a coplanar waveguide (CPW) and it has two input ports. The proposed ultrawideband rectifier has a two-cascaded voltage doubler configuration. This configuration means the proposed rectifier’s input impedance has less sensitivity to frequency variation. Thus, a wide bandwidth can be achieved. For validation, a prototype is designed, fabricated and measured. The measured results show that the axial ratio (AR) bandwidth of the proposed rectenna is from 1.35 to 3.10 GHz (for AR <3 dB). In this frequency range, the rectenna’s power conversion efficiency (PCE) is higher than 55%. These results indicate that the proposed rectenna is highly efficient and suitable for wideband high-efficiency WEH systems.