An Ultrawideband Four-Port Composite Probe With Simultaneous Measurement of Multicomponent Fields and Improvement of Electric-Field Suppression

In this study, an ultrawideband four-port composite probe with simultaneous measurement of multicomponent fields and the improvement of electric-field suppression was developed. The composite probe consists of sensing loops, stripline, via fence, and Sub-Miniature-A connectors. Unlike the traditional composite probes that only measure magnetic-field (
${H} _{x}$
or
${H} _{y}$
) or electric-field (
${E} _{z}$
) components, this proposed probe can detect three orthogonal electromagnetic-field components (
${H} _{x}$
,
${H} _{y}$
, and
${E} _{z}$
) simultaneously by using a pair of cross-orthogonal loops, including a horizontal loop and a vertical loop. Two rows of via fences next to the loops were utilized to suppress unwanted electromagnetic wave modes. To demonstrate the advantages of the composite probe, a simulation model is printed and fabricated based on a five-layered printed circuit board (PCB). A standard microstrip line was applied for characterizing and calibrating the composite probe. The rationality of the multicomponent measurement of the probe was verified by comparing the simulated and measured results. Finally, a near-field scanning system with the composite probe was set up to measure an unknown parallel microstrip line. From the tested results, it can be concluded that the composite probe has a wide working bandwidth (0.01–20 GHz) and a high electric-field suppression performance. In addition, it can accurately test two orthogonal magnetic-field components (
${H} _{\mathbf {x}}$
and
${H} _{y}$
) and an electric-field component (
${E} _{\mathbf {z}}$
).