Design of efficient air core inductors using a partial element equivalent circuit method

This paper proposes an optimization method to improve the efficiency of air core inductors, which are frequently employed in near field communication, wireless power transfer, and power conversion systems. We propose a modification to the PEEC based method, which aims at further reducing the computational complexity associated with complex 3D topologies. The main idea is to optimize 3D structures based on a 2D analysis. The device low frequency behavior is estimated based on the full 3D topology, while corrections resulting from high frequency effects are estimated based on a 2D approximation. As a result, since 2D formulations are used to estimate the high frequency effects, it is possible to obtain small mesh sizes, and hence to decrease the computational load, enabling a fast iterative design process. In addition, the proposed method requires no special commercial software, and can be easily implemented in Matlab. Results are compared to a standard commercial FEM tool, CST EM studio, and the results match well.