On the Use of Dual-Band SIMO- and MIMO-Based Defected Ground Structures in the Design, Characterization, and Validation of RF WPT System

This article reports, for the first time, a single-input-multi-output (SIMO) and a multi-input-multi-output (MIMO)-based dual-band defected ground structure wireless power transfer (DGS-WPT) system. At first, novel equivalent circuits of both the systems are developed using the theory of impedance/admittance matrix and quasi-static approximation. Subsequently, these equivalent circuits are used to perform a thorough investigation and analysis to address the issues related to characterization and cross-coupling in such dual-band WPT systems. As a case study, dual-band SIMO- and MIMO-DGS-WPT systems operating at 300 and 700 MHz are fabricated and characterized while keeping the transmitter (TX) and receiver (RX) at an optimal distance (h) of 18 mm. An excellent agreement between the measured and simulation results demonstrates the effectiveness of the proposed approach. The power transfer efficiency for the SIMO-WPT system is 68.7% and 70% at the design frequencies of 300 and 700 MHz, respectively. Similarly, the corresponding values for the MIMO-WPT system are 75.1% and 73.2%. These results are unique and advance the state-of-the-art significantly.