A Compact Dual-Band Rectifier Using Heterofrequency Independent Matching Technology

This work presents a compact dual-band rectifier using heterofrequency independent matching technology (HIMT) to achieve high conversion efficiency for the application of and wireless power transmission (WPT) systems. The dual-band impedance matching network (IMN) is composed of an L-type matching network and a heterofrequency independent matching network (HIMN). Specifically, the L-type matching network is applied for the fundamental single-band matching and HIMN is applied for the other band matching by employing a series half-wavelength transmission line and a short-ended quarter-wavelength transmission line, which behave as a bandpass structure and is completely independent on the fundamental band matching. In this way, the dual-band rectifier can achieve high efficiency in both two bands and compact size with reduced design difficulty. Theoretical analysis of the dual-band rectifier using HIMN is carried out. For demonstration, a prototype of the dual-band rectifier with a compact size of $17.5 \times 15$ mm2 is fabricated and measured. The measured results show that the maximum conversion efficiency can maintain 72.8% and 69.0% at 2.45 and 5.6 GHz, respectively, with 10.5 dBm input power.