Design of Miniaturized Sub-6 GHz Rectifier With Self-Impedance Matching Technique

This work presents a novel concept of self-impedance matching in rectifier design by integrating a driving rectifier in parallel with a conventional voltage doubler circuit. The input impedance of the wideband rectifier is perfectly matched with the use of driving rectifier, which consists of a half-wave rectifier, a series stub line, and a grounding capacitor. The series stub adjusts the operating frequency and the efficiency bandwidth (EBW) of the proposed rectifier. This approach streamlines the rectifier design by eliminating additional input impedance matching networks and offers simultaneous control of EBW and operating bandwidth. Instead of a conventional lossy microstrip line, a Defected Ground Structure (DGS) is employed to design a high-impedance series stub line which makes the proposed circuit compact with improved quality factor. The experimental results highlight the effectiveness of the proposed rectifier, achieving more than 50% power conversion efficiency (PCE) for the frequency range of 3 GHz to 5.8 GHz, covering entire sub-6 GHz band of the 5G network with minimal variation. The fabricated prototype is the most compact design, with a circuit size of only 0.756 cm2.