Simulation and analysis of a shielding cavity used in on-site radiated emission measurement

In the process of on-site radiated emission test, the background noise as an uncertainty will affect the measurement results, and decrease the reference value of the final results. In order to solve this problem, this paper proposes a shielding cavity with an opening side, the receiving antenna is placed in its interior. The ambient noise can be suppressed by shielding layers, while reducing the impact of electromagnetic environment on the test itself. For studying the restraining level for the background noise signal, this paper utilizes the simulation software based on the finite element method to simulate the shielding cavity, and the distribution of the internal electromagnetic field is analyzed. The simulation results show that the amplitude of the background noise can be attenuated by the shielding cavity to more than 80%, which can preliminarily demonstrate the inhibitory effect of the shielded cavity for the background noise.