Dual‐band CPW rectenna for low input power energy harvesting applications.

A dual‐frequency band low input power rectenna is proposed in this study. The rectenna is comprised of a co‐planar waveguide (CPW) rectifier integrated with a rectangular split ring antenna loaded by a spiral strip line. A single diode series connection topology is used to miniaturise the losses at low input power. A spiral coil in addition to two short circuit stubs are used as a matching network for maximum power transfer between the antenna and the rectifying circuit. The proposed rectenna operates at low input power with relatively high measured RF‐DC conversion efficiency up to 74% at input power of −6.5dBm at the first resonant frequency f1=700MHz and 70% at −4.5dBm at the second operating frequency f2=1.4GHz with a resistive load of 1.9kΩ. The measured rectenna sensitivity (the rectenna ability to receive low power with acceptable conversion efficiency) reaches up to −20dBm with a conversion efficiency of 47 and 36% at f1 and f2, respectively, and a DC output voltage of 0.18V. The measured efficiency is over 50% from −18 to −3.5dBm and from −15 to −1.5dBm at f1 and f2, respectively. [ABSTRACT FROM AUTHOR]