RF Energy Harvesting using Cross-couple Rectifier and DTMOS on SOTB with Phase Effect of Paired RF Inputs

Abstract

This paper presents the design and evaluations of a cross-couple rectifier (CCR) with floating sub-circuit using Dynamic Threshold MOSFET (DTMOS) for RF energy harvesting. The circuit is fabricated using 65nm SOTB CMOS technology. Measurement result shows that circuit exceeds 1000 mV DC output at -9dBm input power. The study also indicates the effect of phase difference between the two RF input signals on the DC output voltage in CMOS CCR. The DC output voltage depends on the phase of the two RF input signals and reaches maximum at the phase difference of the two RF signals is $\pi$. Experimental results demonstrate that the output voltage changes from 950 mV to -100mV when the phase difference varies from $\pi$ to 0 at an RF input power of -10dBm. When the rectifier receives RF signal from the environment at an input power of -35dBm, the DC output voltage changes from 130 mV to -12 mV when the phase changes from $\pi$ to 0.