A Harmonic Suppression Energy Collection Metasurface Insensitive to Load and Input Power for Microwave Power Transmission

This article describes a high-efficiency harmonic suppression metasurface (HSMS) energy collector, which is insensitive to frequency, input power, and load. A method of integrating harmonic suppression function into energy collection metasurface (MS) to improve system conversion efficiency is proposed. Integrated RF synthesis channels in HSMS improve diode power availability and turn-on time. An
$8\times 8$
finite element MS array was designed and fabricated, achieving a conversion efficiency
$_{\mathrm {RF}-\mathrm {ac}}$
of 96%. The measurement results show that the integrated harmonic suppression can improve the efficiency of ac–dc conversion by 2%–4%. In addition, we propose an impedance compression rectifier to reduce the input power and load requirements of the system. Since HSMS eliminates harmonic suppression networks, the rectifier structure is simple and compact. Finally, the system achieved an efficiency of 74.5% at 5.8 GHz with an input power of 18 dBm. Importantly, it shows that HSMS energy collectors can remain efficient over a wide range of power 6–25 dBm and loads of 500–
$2000~\Omega $
. The proposed concept is suitable for high-efficiency microwave power transmission (MPT) systems with different input power and load conditions.