Simultaneous Measurement of Electric and Magnetic Fields With a High-Sensitivity Differential Composite Probe

In this letter, we propose a new high-sensitivity differential composite probe that is capable of measuring the electric- and magnetic fields simultaneously. First, the conventional differential composite probe is theoretically analyzed and studied. Second, a pair of additional loops are introduced into the differential composite probe to enlarge its detection area and improve the frequency response of the proposed probe, which can enhance the detection sensitivity. The proposed probe is etched on a high-frequency, six-layer, printed circuit board. The correspondingly simulated and measured results are given. A standard microstrip line with 50 Ω is utilized to characterize the key parameters of the probe, including the transmission coefficient and calibration factor. Compared with the conventional single-component probe, the proposed probe has a higher detection sensitivity, and it can simultaneously measure electric and magnetic fields.

I. Introduction

Recently, the near-field radio-frequency (RF) probes have become a hot topic due to the outstanding features of identifying unwanted RF electromagnetic interference (EMI) [1], [2], [3], [4], [5], [6]. Various manufactured techniques are proposed to design near-field RF probes with high performance, such as low-temperature co-fired ceramic technology [7], [8], printed circuit board (PCB) technology [9], [10], [11], [12], and the thin-film technique [13]. Compared with these manufactured techniques, the PCB technology is the most commonly used and the lowest cost to design the various near-field probes.