Selective Wireless Power Transmission Through High- $Q$ Flat Waveguide-Ring Resonator on 2-D Waveguide Sheet

2-D waveguide power transmission (2DWPT) can potentially provide a safe and wireless means of electricity transfer. Our goal is to develop a 2DWPT system in which the power is transferred only to special receiver devices and not to other objects. For this purpose, a new high-quality (high-Q) factor receiver coupler is designed, while the Q of other general objects are reduced by a thick insulator layer on the sheet. This contrast in Q enables selective power transmission to the receiver coupler. The coupler forms a flat waveguide-ring resonator together with the insulator layer. Full-wave simulations validate the difference of power extraction between the proposed coupler and flat conductor plate resonators as a standard reference of general objects. The performance of the fabricated coupler is also examined on a large open-edged sheet where a standing wave is generated, as well as on a narrow strip-shaped sheet where the standing wave is eliminated. In the case where eight 50-Ω loaded couplers operate on a 90 cm × 60 cm large waveguide sheet simultaneously, the total microwave transmission efficiency achieved 87.7%.