Aperture size effect on the susceptibility of a PCB inside an enclosure

In this paper susceptibility of a microstrip transmission line as a simple PCB inside an enclosure is studied using the Finite Integral Technique (FIT). Here, the magnitude of transmission coefficient of a two port network model of the system (|S₂₁|) is defined as the susceptibility of the PCB. The first port is the input port of a dipole antenna which propagates the interference wave and the second port is connected to a matched transmission line. The effect of different aperture size and numbers on |S₂₁| is studied and it is shown that large apertures can even increase the disagreeable effects of the interfering wave on the PCB at resonance bandwidth of the perforated enclosure. To validate the results, measurements are performed inside an anechoic chamber.