Shielding effectiveness of double layer rectangular enclosure with aperture to wide band electromagnetic pulse

The transmission line method(TLM) is extended to include higher-order transverse electric(TE) cavity modes which are introduced by aperture coupling and the extended TLM is used to analyze the shielding effectiveness(SE) of double layer rectangular enclosure with apertures to the wide band electromagnetic pulse. The electric SE of single layer with an aperture is compared with that of double layer with apertures. The simulation results show that SE can be improved greatly with double layer shielding and it is worse on the resonance frequency of cavity modes. On the condition of aperture-cavity resonance, SE drops significantly in the center of the inner cavity. From 0.1 GHz to 4.5 GHz, SE has a declining trend as a whole.