Electromagnetic Field Coupling Separation of a Single-Output Magnetic Field Probe Based on Termination Effect

This article presents a method to characterize the performance of a single-output magnetic field probe by separating its intrinsic magnetic field coupling (MFC) and parasitic electric field coupling (EFC). The proposed method utilizes a microstrip line (MSL) with a different termination. The MFC and EFC between the probe and the MSL are formulated based on the theory of electric and magnetic field interaction, using the same structure factor and the transmission model of the MSL. This allows the MFC and EFC to be accurately extracted at low frequencies through the introduction of a correlation factor referred to as the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$A$</tex-math> </inline-formula> factor. To validate the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$A$</tex-math> </inline-formula> factor and the proposed extraction theory for the coexisting MFC and EFC, magnetic field probes with different EFCs were designed and fabricated. The separation and extraction experiments were subsequently performed and analyzed with the aid of electromagnetic field simulation. The results demonstrate that, based on the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$A$</tex-math> </inline-formula> factor, the MFC and EFC can be extracted quantitatively at least in the low-frequency region, in good agreement with the theoretical predictions of their behavior.