Design of a Compact Conformal Circularly Polarized Rectenna

This paper designs a compact conformal circularly polarized rectenna operating at Wi-Fi band for RF energy harvesting. In order to obtain a comparatively compact layout, an annular slot antenna and a rectifying circuit are placed on two sides of the same substrate. The The inner circular metal of the annular slot serves as ground plane of the rectifying circuit. Thus, the entire rectenna has a fairly small size of 55 × 55 × 0.254 mm
³
. Moreover, the rectenna is conformal with a cylindrical carrier. The results shows that slot antenna has the - 10 dB impedance bandwidth band of 17.8% and 3-dB AR bandwidth of 8.2%. The efficiencies of rectifier are greater than 50% for the Wi-Fi band at the input power of -10 dBm and the rectifier has maximum efficiency of 65% at the input power of -4 dBm (2.45 GHz).