Ultrawideband Differential Magnetic Near Field Probe With High Electric Field Suppression

In this paper, an ultrawideband differential magnetic near field probe with high electric field suppression is developed. A pair of differential loops, via fence and shielding vias below the loops are designed to reduce the electric field coupling. It is shown that the electric field suppression of the proposed magnetic-field probe is higher than 30 dB up to 12.9 GHz and 21 dB up to 14 GHz. Due to the differential loops and shielding vias, the proposed magnetic-field probe shows better electric field suppression and sensitivity performance, while maintaining similar spatial resolution. Two other probes with single loop for sensing and without shielding vias are prepared for comparison.