An Active <i>E_zH_xH_y </i> Probe and Its Calibration Matrix for Near-Field Measurement

This paper presents a design of high-sensitive <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E_zH_xH_y</i> probe integrating with low noise amplifiers (LNAs), capable of simultaneously capturing <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E_z</i>, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H_x</i> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H_y</i> in a single scan, thereby significantly enhancing the scanning efficiency. The probe design leverages field-circuit hybrid simulation, with an analysis of the asymmetric output voltage response to <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>z</i></sub>. The LNA integrated in the transmission part of the probe introduces channel imbalances, resulting in inaccuracies in traditional probe calibration methods. To address this issue, a novel calibration matrix is developed in which the imbalance is considered. This method not only is applicable for various three-component probes but can also be theoretically extended to multi-components probes, making it a versatile and general calibration method. Both simulation and measurement results corroborate the exceptional performance of the proposed probe and the calibration matrix, validating their efficacy in practical applications.