3-D Printed Multifocusing Truncated Gutman Lens With High-Efficient MMIC Class-F Load GaAs Rectenna for mm-Wave Battery-Free IoT Application

We introduce an all-dielectric 3-D-printed multifocusing truncated Gutman lens integrated with a high-efficient MMIC class-F load GaAs rectenna for mm-Wave Battery-free IoT applications at 24 GHz in this article. We conduct a detailed analysis of the multifocusing performance of the proposed lens structure using full-wave simulation, revealing the varying position of the focusing spot on the back surface of lens in response to the transmitted beam direction. Benefiting from the cost-effective 3-D printing technique, we fabricate a truncated Gutman lens prototype based on the automatic stacking of perforated dielectric cubes. The near-field phase transform experiment at 24 GHz was carried out to verify the multifocusing performance of the fabricated lens prototype. In addition, unlike the traditional rectifier using a capacitor in previous studies, we design and fabricate a GaAs MMIC rectenna using a single-shunt full-wave rectifier circuit with an F-class load at 24 GHz, achieving a measured maximum rectification efficiency of 47.9% with an input power of 210 mW and a $120 \, \Omega $ resistive load. The mm-Wave wireless power transfer (WPT) experiment further demonstrates the potential of the proposed lens structure for practical mm-Wave IoT WPT applications by enhancing conversion efficiency and reducing sensitivity to incident beam angles.