A modified cross coupled rectifier based charge pump for energy harvesting using RF to DC conversion

This paper presents a CMOS based RF-to-DC converter using a proposed cross-coupled charge pump for energy harvesting. Extraction of high DC voltages from rectifier block in the charge pumps is always a serious bottleneck for RF energy scavenging. One of the dominant obstacles is the threshold voltage (Vth) of the MOS transistor. In this work we are proposing a simple mechanism to eliminate the Vth dependence in MOS transistor, which inherently improves the DC extraction ability of charge pump. The proposed system is implemented in 180nm CMOS technology and simulated using Cadence Spectre. The extracted DC voltage from RF energy is selected as Figure of Merit. It is found using simulation that the modified charge pump shows a high efficiency in DC extraction from RF signal than the conventional cross coupled rectifier based charge pump.