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.