Design of a Wireless Power Transfer System to Power Wireless Sensors Remotely Using Uhf

Abstract

A wireless power transfer system is designed to power remotely placed wireless sensors using UHF band. For receiving purpose, a small and compact, bi-quad antenna is designed which has a fractional bandwidth of 6.89% (443.65 MHz-475.5 MHz). The receiver antenna is uni-directional and has the maximum gain of 9.7 dBi. The overall dimensions of the antenna including the reflective ground plane are 50 cm × 30 cm × 16 cm (0.767λ × 0.46λ × 0.172λ at 460 MHz). A General Mobile Radio Service (GMRS) radio license is obtained and a frequency of 462.55 MHz is used during the test measurement. The maximum achieved effective distance is 150 ft with 3.52 V, which is enough for powering most of the commercial sensors.