Effects of Aperture Dimensions on Shielding Effectiveness of the QiTai Radio Telescope Multi-Layer Shielding Structure

Multi-layer shielding effectively suppresses radiated emission from electronic equipment near the focal point of a telescope, where electromagnetic leakage through apertures is the primary factor limiting shielding effectiveness. Investigating the impact of aperture leakage on overall shielding performance provides critical technical support for multi-layer shield design. To address the electromagnetic protection requirements for equipment near the focal region of the QiTai radio telescope, this study validates the accuracy and frequency adaptability of Robinson's theory and the Baum-Liu-Tesche equation in calculating multi-layer shield aperture leakage. Statistically permissible aperture dimensions satisfying shielding requirements were determined for the 0.3-1.5 GHz band using these methods. Finite Integral Technique simulations further quantified compliant aperture dimensions for the 1.5-6 GHz band, demonstrating that rectangular apertures with dimensions of 3 mm × 3 mm or 4 mm × 1 mm, or circular apertures with diameters of ≤ 3.3 mm, meet the QiTai radio telescope multi-layer shielding requirements.