A General Mutual Coupling Model of MIMO Capacitive Coupling Interface with Arbitrary Number of Ports

A general mutual coupling model of multiple input and/or multiple output (MIMO) capacitive coupling interface with an arbitrary number of ports is proposed. In the model proposed in this letter, all the capacitances between the metal plates are taken into account. The self-capacitance of each port and mutual capacitances between the two ports are defined, and a simple equivalent circuit composed of self capacitances and current-controlled voltage sources is obtained. The proposed model helps to reduce the complexity of the MIMO capacitive coupling interface and can be used to simplify the analysis of the power transfer performance of MIMO capacitive power transfer systems. An example capacitive coupling interface setup with two input ports and two output ports is built and tested. The measured and model-based theoretical results of the self and mutual capacitances of the capacitive coupling interface are compared and found to be in good consistency, which verifies the correctness of the proposed model.