No abstract

In this Letter, a wideband antenna operating in a portion of the L-Band frequency range is presented. The antenna is based on a prefractal geometry belonging to Julia Set and optimized by means of hybrid-coded genetic algorithm to minimize size and voltage-standingwave-ratio coefficient and consequently meet physical and electrical requirements. After numerical assessment, a prototype of the global positioning system-band antenna has been built and experimentally tested. The comparison between numerical and experimental data shows a good agreement and the satisfaction of requirements.ABSTRACT: In this letter, a high efficiency RF-DC conversion circuit for RF energy harvesting system (EHS) is proposed. The proposed circuit consists of Villard voltage doubler, the input and output termination networks which can suppress the unwanted RF signals produced by Schottky diodes. The fabricated circuit operating at 2.45 GHz has a maximum RF-DC conversion efficiency of 83.37% and output voltage of 11.30 V at an input RF power of 140 mW. The proposed circuit has an advantage of simple design which helps to reduce the design cost of EHSs.