Compact and Wide-band Efficiency Improved RF Differential Rectifier for Wireless Energy Harvesting

This paper presents a novel design of radiofrequency (RF) differential rectifier (DR) for harvesting power as low as 0 dBm. The proposed configuration aims to improve efficiency over extended bandwidth of operation, and further size reduction for low profile RF rectifier circuit. The developed design introduces a balanced output voltage which is suitable for biasing most of the analog integrated circuits, e.g, all circuits based transistor requires ±Vdc. In addition, the proposed topology provides a measured RF-DC efficiency more than 30% over a relatively wide bandwidth (550M H z) from 0.95GH z to 1.5GHz. Commercial balanced-unbalanced (BALUN) component is used for port transformation. Experimental results show that the system can work with different carrier frequencies and the proposed converter can provide a regulated output voltage of ±1V over the proposed frequency band at RF input power Pin=5dBm, The peak conversion efficiency of the whole system is 57.5% at 1.1GHz.