A High-Efficiency Rectifier With Ultra-Wide Input Power Range Based on Cooperative Structure

As the most critical component of wireless power transfer (WPT) and wireless energy harvesting (WEH) systems, the rectifier is required to exhibit excellent performance. Most existing works focus on improvement in efficiency and bandwidth for a given input power level. However, in practice, the input power level is usually unpredictable. Therefore, a rectifier which exhibits high efficiency over a wide range of input power is highly desirable. But existing structures can only achieve limited input power range with a complex configuration. A novel cooperative structure using two diodes with diverse characteristics is proposed to solve these problems. Theoretical analysis and a comparison of performances with conventional ones are carried out. For validation in different application scenarios, two rectifiers operating at 2.4 GHz were designed, fabricated, and measured. For the proposed rectifier I, the measured efficiency is larger than 60% over an input power range from 3.5 to 25.2 dBm. While for rectifier II, the measured efficiency remains over 50% with input power from -6 to 26.5 dBm. These results demonstrated the effectiveness of the proposed structure in extending the input power range, especially for the low power region. Furthermore, the application in a WPT system was also demonstrated.