A Design of Rectifier with High-Voltage Conversion Gain in 65-nm CMOS Technology for Indoor Light and RF Energy Harvesting

In rectifier design, the key parameters are the voltage conversion ratio and the power conversion efficiency. A new circuit design approach is presented in which a capacitor-based, cross-coupled differential-driven topology is used to boost the voltage conversion ratio. The scheme also integrates an auxiliary current path to lift the power conversion efficiency. To demonstrate its practicality, two three stage rectifiers were designed and fabricated in a standard 65 nm CMOS technology. The designs were tested under various conditions to assess their performance. The first rectifier targets indoor light energy harvesting applications. It achieves a peak voltage conversion ratio of 3.94 and a maximum
power conversion efficiency of 58.7% when driving a 600 Ω load, while supplying over 2mA of output current. The second rectifier is optimized for RF energy harvesting at 2.4GHz. Experimental results indicate that it can deliver 70 µA to a 50 kΩ load, with a peak voltage conversion ratio of 5 and a power conversion efficiency of 17.5%.