RF Energy Harvesting with Wide Input Power Range

An innovative CMOS differential dual-path rectifier design is proposed with an extended dynamic range of input RF power, enabling wireless power transfer over varying distances. The key feature of this design is the implementation of an adaptive control circuit that ensures the independent operation of one path without interference. The dynamic switching mechanism optimizes energy harvesting based on the input power conditions. To enhance efficiency and functionality, Native-NMOS is employed, allowing the rectifier to efficiently receive low input power and significantly improve its overall performance. This work operates successfully at UHF at 900MHz. Utilizing $10 \mathrm{k} \Omega$ LDO’s equivalent resistance load and 60pF capacitor energy storage, the measured power conversion efficiency can achieve above 20%. At an input power of 4dBm, the efficiency reaches 35.6% with an output voltage above 1.8V. The test chip has been implemented in TSMC $0.18 \mu \mathrm{m}$ process with a chip area of $0.454 \times 0.415 \mathrm{~mm}^{2}$. At an input power range from −4dBm to 8dBm, the power consumption is from 0.53mW to 13.1mW.