A Novel Design of High-Efficiency Dual-Band Rectifier Based on Coupled Transmission Line for Wireless Power Transfer and Energy Harvesting

In this letter, a novel design of high-efficiency dual-band (DB) rectifier based on coupled transmission line (CTL) is presented. The proposed structure is separated into two parts. Part A uses a CTL to suppress the second harmonic of both the frequencies concurrently, enabling a DB-efficient power recycling mechanism with low design complexity and compact dimension. Part B implements a DB fundamental matching network to the source of 50
$\Omega $
with a combination of a CTL and a single transmission line (TL) which also terminates the harmonics beyond the second-order for further power conversion efficiency (PCE) enhancement. Both the parts are investigated in the closed-form equations. For validation, a Schottky-diode-based rectifier is simulated, fabricated, and measured at two frequencies of 0.915 and 2.4 GHz. The experimental results show that the highest PCE is achieved at 81.98% and 77.85% for 0.915 and 2.4 GHz, respectively, with an optimal load resistance of 680
$\Omega $
. Moreover, the 50% over PCE remains within a wide dynamic range of 19.5 dB at 0.915 GHz and 18.5 dB at 2.4 GHz. Compared with the state-of-the-art works, the proposed rectifier exhibits advantages of high PCE and compactness.