Design of SEMI-Anechoic Chambers with Arbitrary Absorbers using Circuital Techniques
Luis Nuño-Fernández, Fernando D. Quesada, Juan Vicente Balbastre Tejedor, Alejandro Díaz‐Morcillo · 2002
Semi-anechoic chambers are one of the most important elements of an EMC test laboratory and they play a capital role in both radiated emission and immunity tests. International standards specify the required characteristics for chambers used in official laboratories. The design of semi-anechoic chambers matching these international standard requirements is not an easy task. Although during the last thirty years several numerical techniques have been successfully used for solving electromagnetic problems, the design of semi-anechoic chambers still remains a challenging problem due to the wide span of operating frequencies. Difference techniques, like the Finite Element Method or the Finite Difference in Time Domain, can be hardly applied to actual chambers above 100 MHz and ray tracing techniques do not work well below 300 MHz. In this work a new tool for the design of semi-anechoic chambers for frequencies between 30 and 300 MHz is presented. This method combines the efficiency of the circuital techniques with the versatility of the Finite Element Method. The proposed method has been validated with an actual chamber and very good agreement between simulations and measurements has been observed.