An Ultrawideband Differential Magnetic-Field Probe for Near-Field Scanning

Abstract

In this study, a differential magnetic-field probe capable of measuring two orthogonal magnetic-field components is developed. Different from conventional single-component magnetic-field probes with a detection loop, the proposed probe consists of two orthogonal detection loops and a short-circuit point. Two orthogonal induced loops are used to sense the orthogonal magnetic-field components ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${H} _{y}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${H} _{x}$ </tex-math></inline-formula> ). In addition, many grounded vias are inserted into the probe to suppress unwanted electromagnetic modes. To prove the design accuracy, the presented probe is simulated, measured, and analyzed. It is observed that the working frequency of the probe is 1 MHz–20 GHz.