High efficiency dual‐band rectifiers with wide input power range for wireless power transfer

Abstract

A watt‐scale dual‐band rectifier with excellent efficiency and a wide input power range is proposed in this letter. The rectifier is composed of two stages. In the first stage, a novel impedance‐matching network with four transmission lines (TLINs) is proposed, which can independently change the input impedance of each band over a large input power range. This approach by deriving closed‐form analytical equations to obtain an exact solution. To test the parameters of the first part of the TLINs in validation and to guarantee excellent efficiency, two TLINs are used in the second stage to control the harmonics. At 0 dBm, the power conversion efficiency (PCE) is 51.2% and 56.7% at 2.4 and 5.8 GHz, respectively, at a load of 1.2 kΩ. At 2.4 GHz, PCE reaches a peak of 68% at 13 dBm. At 5.8 GHz, PCE enhances up to 89% at 17 dBm. At 2.4 and 5.8 GHz, the PCE exceeds 70% of the peak over a wide input power range of −3 to 18 and 1.5–18 dBm, respectively. For verification, the proposed rectifier is fabricated. The simulation results are consistent with the measurements. The proposed rectifier performs well in terms of compactness and rectification effectiveness. It provides a solution for powering low‐power devices.