A New Dual-Component Magnetic Field Probe for EMI Test

This paper presents a new magnetic probe that achieves two different magnetic-field components in near-field scanning measurements. The proposed probe employs a composite architecture comprising three key elements: a pair of conventional monopoles, a T-shaped shorted loop, and two interconnected vias. Different from existing solutions using differential or single U-shaped loops for electromagnetic-field (HyandEz) detection, this innovative architecture through integration of monopoles and T-shaped shorted loop successfully enables synchronous detection of vertically orthogonal magnetic field components (HyandHz). Moreover, the probe was fabricated using four-layer PCB technology and validated through a near-field measurement system incorporating standard calibration kits. Simulated and measured results reveal the detection sensitivity of the proposed magnetic probe along they-direction is greater than -45 dB at 3-15 GHz, but it is more than -50 dB at 4.5-15 GHz along the z-direction. Therefore, the proposed probe can achieve simultaneous precise measurement of dual orthogonal magnetic field components (HyandHz), and has a wider operational bandwidth (4.5-15 GHz).