A Compact and Highly Efficient Circularly Polarized UWB Rectenna for Wireless Power Transfer Application

In this paper, a low-profile and compact circular polarized (CP) rectenna with a compact ultrawideband (UWB) rectifier circuit to transfer power wirelessly at 3.2 GHz is presented. The size of the proposed rectenna is 0.19λ
o
× 0.19λ
o
. The new L-L input impedance matching demonstrates increased stability and maintains a consistently stable power conversion efficiency across a wider range of input power levels. With a compact size, the UWB rectifier offers an impressively wide bandwidth spanning from 2 to 3.5 GHz. The maximum power conversion efficiency (PCE) of 60% has been measured with a 50Ω load at 3.2 GHz. The power conversion efficiency (PCE) of the rectifier reaches up to 45% at -10 dBm input power level at 3.2 GHz frequency. The maximum PCE of the rectifier is 60% at 0 dBm input power. The proposed rectenna offers excellent resilience to misalignment due to its circularly polarized receiving antenna.