Design Methodology of Resonant H-field Probe with a High Bandwidth in Near-Field Measurements

Resonant near-field probes can be used for localization and characterization of noise sources in electromagnetic compatibility (EMC) applications. However, the usability of a resonant probe is limited by its narrow bandwidth. This article presents a design and the corresponding optimization flow which improves the bandwidth of a resonant H-field probe by adapting the impedance variation ratio of the transmission line balun. Compared to the traditional design, the proposed one achieves triple bandwidth with only 2.7 dB sensitivity loss. The improved design enables a more efficient scanning in real applications.