Application of a magnetic near-field probe to the differentiation of defective connections

A new type of probe for the differentiation of defective connections from fully functioning ones between metal plates such as the frame ground has been designed, prototyped, and evaluated. The probe utilizes a dual loop near-field antenna to detect the magnetic near-field due to the current at the connecting point, and an oscillation circuit has been integrated as a stimulus. The prototype probe has been designed and made using a FR-4 PCB. The actual measurements were performed by using a prototyped probe with two metal plates connected at a certain point. The measured results revealed that the peak of the induced voltage could indicate the connecting point of the plates after observing high frequency behavior. A 3D electromagnetic simulation has also been performed, suggesting the results are reasonable.