Simultaneous Measurement of Four Electromagnetic Components With a Four-Port Composite Probe for Near-Field Scanning

Abstract

In this work, a four-port composite probe, based on the probe compensation technique, is proposed to simultaneously measure four different electromagnetic components ( $H_{y},E_{z},E_{y}$ , and $H_{z}$ ). The proposed composite probe is made of a pair of curved U-shaped loops as the detection section, four strip-lines as the transmission section, and four sub-miniature A (SMA) connectors as the output section. Some via fences and via arrays are introduced into the proposed probe and optimized to realize broadband operation at 4–15 GHz. Note that these curved U-shaped loops, strip-line, SMA connectors, and via fences and via arrays are all symmetrically placed to minimize unwanted electromagnetic coupling. Moreover, a microstrip line (ML) and slot-line (SL) with 50- $\Omega $ matching loads are together utilized as calibration kits to characterize and calibrate the proposed composite probe. Finally, to verify the effectiveness of the design, the proposed four-port composite probe was simulated by high-frequency electromagnetic software, manufactured on a four-layer printed circuit board (PCB), and characterized by a near-field scanning measurement system with the above calibration kits. Simulated and measured results reveal that the proposed four-port composite not only achieves the simultaneous measurement of four electromagnetic field components ( $H_{y},E_{z},E_{y}$ , and $H_{z}$ ) but also has a wide working bandwidth (4–15 GHz).