High-Efficiency Rectifier with Wide Input Power Rage Based on a Small Capacitor in Parallel with the Diode

Based on the elimination of the input matching circuit a high-efficiency microwave rectifier is presented in this work. In the proposed design, a small capacitor is in parallel with the diode, and a λg=8 short circuited stub is placed between the cathode of diode and ground plane. This small capacitor can modify the real part of the diode impedance, and then the λg=8 cancels the yield capacitive impedance. Meanwhile, this λg=8 short circuited stub presents a high reactance at the second harmonic. The fabricated rectifier has a maximum RF-DC conversion efficiency (PCE) of 86.7% at 24.8 dBm input power. The measured efficiency remains above 70% with the input power from 8.2 to 25dBm and the operating frequency from 1.5 to 2.2 GHz.