The application of improved FDTD algorithm based on mode-matching in shielding cavity

Abstract

Due to the increasing complexity of the electromagnetic environment, the cavity with apertures are used more and more widely in electromagnetic shielding. At present, the time domain finite difference (FDTD) method has a good application effect for the transmission line response problem of a double-layer shield cavity with apertures, but this method usually encounters the boundary problem of semi-open and open areas. Due to the limited computing resources, the truncation of the FDTD region has an impact on the accuracy and speed of the calculation because that is very important. Based on that, this paper puts forward a method of combining mode-matching method with FDTD algorithm, which overcomes the limitation that mode-matching method can only be used for regular waveguide analysis and uses mode-matching method to solve FDTD boundary problems. The improved FDTD algorithm based on mode-matching method enhances the accuracy of the algorithm and guarantees the calculation speed.

Analytical and numerical models compared with measurements for analysis of electromagnetic radiation through apertures of a metallic enclosure

“…The FDTD method has been widely applied to solving different types of electromagnetic scattering problems [7,10]. It possesses the advantages of simple implementation for relatively complex problems, high accuracy and the ability of work with a wide range of frequencies, stimuli, objects, environments and response locations.…”

“…A rigorous approach to this problem would require the solution of a complex scattering problem, taking into account the re-irradiation from the enclosure. Since a closed-form solution to this kind of problem is generally not available, numerical methods have been applied including transmission-line-matrix (TLM) method [6], finite-difference time-domain (FDTD) method [7,10] and method of moments (MoM) [11,12]. Although they are quite accurate, it is difficult for EMC designers to use them to investigate the effect of design parameters on shielding effectiveness during the product design stage because they are computationally intensive.…”