A Nonlinear Rectifying Diode Model for Low and High Power Levels in Microwave Regime

This letter discusses a nonlinear Schottky diode modeling method for microwave rectifier design and fast optimal diode selection. Diode power losses due to the diode series resistor, junction capacitor, built-in potential, and breakdown voltage are analyzed based on the current–voltage diode characteristic curve which can accurately predict the maximum achievable power conversion efficiency (PCE) of the rectifier circuit in both low and high input power regions. Closed-form equations are then derived to predict the PCE of a given diode at a specific working condition (input power, frequency, and load value), which can be a very useful tool for fast optimal diode selection. The proposed model has been verified both numerically and experimentally for different Schottky diodes and working frequencies, finding very good correspondence with circuit simulation results and confirming the reliability of the discussed method.