Design and testing of rectifying antenna for RF energy scavenging in GSM 900 band

Abstract

The energy scavenging techniques are found as sustainable solution to the increasing energy needs. The increased use of wireless devices and installation of cell phone towers in the recent years produces abundant radio frequency (RF) energy in the ambient environment. This makes the RF energy scavenging as an attractive possibility. The energy scavenging module consists of an antenna to capture RF energy and appropriate circuitry for RF to DC conversion. In the present work, a microstrip-fed printed shorted ring slot antenna with circular polarization is chosen for collecting RF energy. The bridge rectifier with Schottky diode is used for RF to DC conversion. The novelty of the work lies in the design of a highly efficient yet simple and compact rectenna module for energy harvesting in the GSM 900 band using circularly polarized antenna. The antenna structure is designed and optimized using CST microwave studio. The bridge rectifier circuit is designed using SPICE software. The measured results for the prototype rectenna system tested for energy scavenging in the laboratory environment are also presented. The whole rectenna system shows an overall efficiency of 45.47% for incident power density of 162 μW/cm2. The harvested power may be stored to power sensor networks and also used for recharging the batteries of wireless devices like mobile phones.