A study on MOSFET rectifiers with transistors operating in the weak inversion region

Today´s energy harvesting circuits have to harvest energy from very weak sources demanding high sensitivity and high efficiency. In this paper it is presented a study on rectifiers used in radio frequency (RF) energy harvesting systems with transistors operating in weak-inversion region, where the losses due to reverse current become comparable to the direct (or charge) current. The study compares three rectifier topologies and makes use of all transistors terminals to improve performance, increasing the direct current and reducing the reverse current. The results show that connecting an anti-phase signal to the transistor´s gate and bulk terminals improves the rectifier´s delivered power.