Evaluation of radiated emissions from circuit boards by non-contact measurement techniques

In this study, three configurations associated with a non-contact measurement technique were developed to estimate the resonant frequencies of a circuit on a PCB. A model based on the wireless power transfer circuit was developed to describe the theory behind the non-contact measurement system. A loop trace on a PCB excited by a 20-MHz clock generator was used to validate the non-contact measurement technique. Measured results show that the developed non-contact measurement system can be used to detect the resonant frequencies of a circuit board and hence to estimate the dominant frequencies of the radiated emissions from the circuit board with excitation.