Efficient Low-Frequency Breakdown Free Full-Wave PEEC Modeling Based on Geometrical Optics DCIM

The partial element equivalent circuit (PEEC) modeling based on geometrical optics discrete complex image method (GODCIM) is proposed. In GODCIM, the spectral domain dyadic Green´s functions for layered media (DGFLM) are expanded into a geometrical optics series. The coefficient of each term is related to the Green´s function for a half-space problem and then is expanded into an exponential series with frequency-independent parameters, which avoids the repeated computations of the complex images at each frequency brought by the conventional discrete complex image method (DCIM) and facilitates its application to the PEEC method to solve the layer medium problems. To address the low-frequency breakdown issue in PEEC modeling, a capacitor-opened (CO) model is introduced, which leads to fewer unknowns comparing with modified nodal analysis (MNA) model. The calculation errors between CO and MNA model are verified to be negligible. Easy switching between CO model and modified loop analysis (MLA) model is realized by a switching criterion based on Kalman filter which leads to a full spectrum simulation from dc to high frequencies. Numerical results ranged from Hz to 30 GHz are given to validate the proposed method.