Modeling of Complex Radome-Enclosed Antennas Mounted on Large-Size Platform Using Double-Nested Iterative VSIE-MSI-PO Method

A novel double-nested iterative hybrid method that combines the volume-surface integral equation (VSIE), the modified surface integration (MSI) method, and the physical optics (PO) is presented to analyze electromagnetic (EM) radiation of radome-enclosed antennas (REA) installed on large-size perfect electric conductor (PEC) platforms. The entire target is firstly decomposed into the antenna, radome, and platform regions according to the structural characteristics of respective parts. The full-wave VSIE is used to analyze the complex antenna, and the MSI is applied to model the multilayer dielectric radome of arbitrary shape. Via the approximate equivalence principle, the VSIE is cascaded with the MSI in the inner iteration loop to efficiently account for the mutual couplings between the antenna and the radome. In order to consider the interactions among the platform and the REA, the forward and backward reactions between the PO currents on the platform and the equivalent EM currents in the REA are computed in the outer iteration loop iteratively until final equilibrium is achieved. Most computations involved in the interactions between different regions are accelerated by the multilevel fast multipole algorithm (MLFMA), which makes the proposed method highly efficient in terms of computational time and memory cost. Numerical results show that this approach provides a fast and efficient solution of EM radiation from the REA mounted on large PEC platforms.