Fast Time-Domain Analysis of a Metallic Enclosure With Arbitrary-Shaped Apertures by Marching-on-in-Degree

In this paper, an efficient time-domain technique is introduced for transient analysis of a rectangular metallic enclosure with arbitrary-shaped apertures. The surface equivalent theorem is applied to divide the problem into two separated regions. Then, assuming the magnetic current density on the apertures surface as the unknown of the problem, the governing mixed potential integral equation (MPIE) is derived. Here, to solve the resultant MPIE, we use a marching-on-in-degree (MOD) scheme with the weighted Laguerre polynomials as the entire-domain temporal basis functions. As well, in order to treat the arbitrary-shaped apertures, Rao-Wilton-Glisson spatial basis function is applied. In addition, to improve the efficiency of the proposed method, we apply some accelerating techniques that make the developed MOD method more efficient than the well-known Computer Simulation Technology finite integration technique, even for highly resonating enclosures.