A Feasibility Study of Representing the Electric Field in Perforated Rectangular Enclosure Based on Modal Expansion Method

In this letter, the modal expansion method (MEM) based on orthogonal property of resonant modes is utilized to represent the electric field in a perforated rectangular enclosure. By applying inner product between electric field obtained by finite integration technique (FIT) and transverse electric (TE) or transverse magnetic (TM) mode field respectively, the mode coefficient for each contributing mode can be accurately obtained over the modal bandwidth. Then the electric field in a perforated rectangular enclosure can be represented by the superposition of contributing mode fields multiplying their corresponding mode coefficients. And the figures of mode coefficients' magnitude and phase give an intuitive understanding of the internal electric field. The statistical properties of internal electric fields obtained by FIT and MEM are in agreement with each other. MEM provides a better understanding of the electromagnetic environment in perforated enclosures.