DefinePK

Abstract

The functional (Differential-Mode) signals on Printed Circuit Board (PCB)-traces are not possibly responsible for higher emissions. However, they can induce unwanted Common–Mode (CM) signals on the nearby metallic structures such as PCB-attached cables. Commonly, PCB-attached cables can act as unintentional antenna resulting in higher emissions that may make the PCB easily fail to meet the Electromagnetic Compatibility (EMC) regulatory compliance test. This process requires repeating all the product-building procedures to obtain the optimum design of the prototype, which increases the unit cost, as well as delay in the product marketing. Therefore, an early prediction of CM Radiated Emissions (RE) is helpful for circuit designers to avoid the RE issues before the first prototype is built. PCB- REs are estimated using 3D-full wave numerical solver. However, it is not practical option since it requires intensive computational time. It also does not provide insight into how the electric/magnetic coupling occurs. In this paper, the imbalance difference theory, which has shown successful demonstration in the low frequencies, is adopted for high frequencies. Based on this theory, a mathematical solution is developed for estimating CM-RE from cables attached to high speed PCB. For verification of the proposed model, an open-circuit PCB-configuration is used to validate the proposed mathematical model. Then, the results obtained from this model are compared with results obtained from 3D-HFSS full wave simulation and a good agreement is obtained between the two results.