A system level enclosure (chassis) resonance evaluation methodology and its applications

This paper presents a methodology of evaluating the resonance inside an enclosure which is caused by the resonance of the printed circuit board (PCB) installed inside the chassis. The radiation emitted from the slots on the surface of the enclosure can also be calculated. The paper demonstrates the elimination of such enclosure resonance by placing decoupling capacitors on board to remove the PCB resonance. As a consequence, the radiation from those slots on the enclosure surface is reduced also. The methodology presented here is useful in system level EMC control. The paper also illustrates that power delivery system design is closely related to system level EMC control.