A Quad-band Rectifier Design with Improved Matching Bandwidth for RF Energy Harvesting Applications

A quad-band energy harvester is proposed here. The harvester is formed of rectifiers and matching circuits at different frequency bands: GSM-900 (890-960 MHz), GSM-1800 (1800-1870 MHz), ISM 2.45 GHz (2.45-2.457 GHz) and LTE-band 7 (2.6-2.67 GHz). The harvester is formed of two dual-band matching circuits and two rectifiers instead of the conventional design with four single-band matching circuits and four rectifiers. The matching circuits are designed with improved matching bandwidth by employing several microstrip stubs to compensate for the limited matching bandwidth of the non-linear rectifier. Each rectifier is a four-stage voltage doubler with HSMS 285x Schottky diodes. The RF-DC conversion efficiency is simulated over frequency for various input power levels.