Novel Compact and Broadband Frequency-Selectable Rectennas for a Wide Input-Power and Load Impedance Range

Wireless power transfer (WPT) and wireless energy harvesting (WEH) using rectennas are becoming an emerging technology. This paper presents a novel design method for a rectenna suitable for a wide range of selectable operating frequency band, input power level, and load impedance. Most importantly, it is realized without using complex impedance matching networks which shows significant advantages over existing rectennas in terms of the structure and cost. A rectenna example has been designed, made, and tested using this novel method. The proposed rectenna has a compact size of 90 × 90 × 1.58 mm
³
and operates at four different frequency bands that are selectable from 1.1 to 2.7 GHz. Over 60% (up to 85%) energy conversion efficiency is achieved for the input power from 0 to 15 dBm and load impedance between 700 and 4500 Ω. The rectenna shows excellent performance for the target applications (WPT and WEH) with a much-simplified structure and reduced cost.