High gain pentagonal loop rectifying antenna

Abstract

In this article, a high gain rectifying antenna using a pair of pentagonal loops has been developed for wireless power transfer at 5.8 GHz. For a long range wireless power transfer, the rectenna system requires high gain and high conversion efficiency. The proposed rectenna system consists of a pair of pentagonal loop antennas to achieve high gain characteristics, an impedance transformer, and a rectifying circuit which are designed on a CPS (Coplanar stripline) structure. A metal reflector is also placed for achieving higher gain characteristics in a broadside direction. A CPS to microstrip line balun is designed to verify performance of the pentagonal loop antennas based on CPS structure. The fabricated pentagonal antenna demonstrates high gain of 10.1 dBi, and it results in receiving more RF energy from a designated source. An impedance transformer is designed to change the antenna's input impedance to diode's input impedance and block higher order signals coming back from the rectifying diode. To obtain high conversion efficiency, several load resistors are used. The proposed rectenna system based on CPS pentagonal loops shows measured conversion efficiency of 75% at 5.8 GHz, and its performance has been verified through simulation and measurement.

Optimization Design Methodology of Broadband or Multiband Antenna for Rf Energy Harvesting Applications

“…Additional important features for antennas suitably used in RFEH applications are complex reflection coefficient and impedance frequency bands [22]. In recent reports, different PAs with matching network elimination have been proposed for rectennas, such as hollowed-out square loop antenna [8], crossed off-center-fed dipole antenna [6], and a pair of pentagonal loops [23]. Therefore, rectennas having compact sizes and improved PCE performance over the broadband or various frequency bands are successively reported in previous literatures.…”

A compact hollowed‐out loop rectenna without matching network for wireless sensor applications

“…Loop antenna is a more suitable choice to adapt small sensor compared with other antennas. In Reference 14, a rectifying antenna using a pair of pentagonal loops for wireless power transfer is proposed. A compact fractal loop rectenna with a power distribution rectifier directly integrated in the inside of the antenna is designed in Reference 15.…”