A 2.4-GHz Mid-Field CMOS Wireless Power Receiver Achieving 46% Maximum PCE and 163-mW Output Power
This work presents a 2.4-GHz power receiver using CMOS technology for the next-generation sub-Watt-level mid-field wireless charging. The power receiver mainly consists of an on-board matching network and an integrated two-stage differential cross-connected (CC) rectifier. When designing the CC rectifier, we use a special routing consideration for the on-chip load capacitor CL for reducing the effect of the routing parasitic inductance. By separating the input power source ground and the rectifier ground on the PCB, we designed the differential rectifier directly connected to the single-ended matching network and the power source without using a balun, which significantly reduces the design complexity. Also, the microstrip line (ML) manufactured on the Rogers 4003 substrate is co-designed with the bonding wire for a precise matching. We use the 1.8-V I/O devices in a 28-nm Bulk CMOS for the rectifier. Measurement results show that the power receiver, including the matching network and the rectifier, achieves a 46% peak power conversion efficiency (PCE) at 163-mW DC output power
Mid-field wireless power transfer, power at a distance, power receiver, CMOS, differential cross-connected rectifier.