Notice of RetractionAnalysis of resonance frequency for rectangular cavity with apertures and embedded materials

As the shielding effectiveness is greatly influenced by cavity resonance, the resonance frequency of rectangular cavity is simulated numerically using the finite-difference time-domain (FDTD) method. The influence of aperture size, embedded metal and nonmetal materials on resonance frequency of cavity is analyzed. Computation results indicate that shielding performance decreases with increment of frequency, and it decreases to a great extent at the resonance frequencies. Resonance frequency of cavity is determined not only by the geometry size of cavity, but also by the size of aperture and the embedded object. Existence of aperture corresponds to increasing of electromagnetic size of resonance cavity, which will reduce the resonance frequency. The nonmetal material embedded in the cavity will depress the resonance frequency of cavity, while metal embedded in the cavity will increase the resonance frequency of cavity.