Rectifiers Based on Quadrature Hybrid Coupler with Improved Performance for Energy Harvesting

This paper presents a method for enhancing RF-dc conversion efficiency of the rectifier based on inkjet-printed quadrature based hybrid coupler (QHC) for wireless energy transfer systems. The input matching network and output load of the rectifier are optimized for optimal RF-dc conversion efficiency. Improvement of about 16 dB input power range is achieved for RF-dc conversion efficiency of 60%. The simulated efficiencies of the rectifiers with and without coupler for 3 MHz LTE signals and output power spectra densities at 1.5 GHz are illustrated.