A pair of parallel differentialmagnetic‐fieldprobes with high measurement accuracy and highelectric‐fieldsuppression ratio

Abstract

Magnetic-field probes can be used for electromagnetic interference measurement of high-speed circuits. The main magnetic probe performance includes sensitivity, spatial resolution, electric-field suppression ratio (EFSR), and measurement accuracy. In this article, a pair of differential magnetic-field probes is proposed to improve measurement accuracy without reducing sensitivity. The proposed differential probes consist of two asymmetric loop probes, which are designed in the same plane and separated by a row of periodic vias. The proposed differential probes are fabricated under PCB process. High accuracy can be achieved by measuring difference between outputs of the two probes. In addition, EFSR can be improved by size optimization of the differential magnetic-field probes. Simulation and measurement results show the operating bandwidth is from 100 MHz to 12 GHz, the measurement error is 3.4% and the EFSR is about 40 dB. The proposed probes have higher measurement accuracy and higher EFSR than the conventional single probe, and larger operation bandwidth than the stacked differential probes.

A two‐turn loop active magnetic field probe design for high sensitivity near‐field measurement

“…But sometimes, max(U(y)| 𝜃=90 • ) will also appear at y = 0, which may be due to leaked magnetic fields [22]. For the above two cases, Equation (10) has some representational significance, and to some extent, it represents the ability of the probe to suppress the unwanted field. According to the above definition, the measured differential electric field suppression parameters are shown in Figure 10.…”

“…The following EMC problems include three aspects: (1) immunity ability decreases due to the smaller supply voltage of microcontroller; (2) the high power density of power electronic device brings the improvement of the emission intensity of the interference source; (3) the interference coupling efficiency increases due to the increase of working frequency and the decrease of dimension spacing. In order to analyze and solve these prob-lems, near-field probes for a variety of processes and detection structures are proposed [3][4][5][6][7][8][9][10]. These probes are usually used to analyze electromagnetic interference (EMI) [11], assess electromagnetic emission level [12,13], locate EMI sources [14,15], reconstruct EMI source [16,17], locate the faults of IGBT [18], implement over-the-air test of dipole and patch antenna arrays [19], detect and analyze of fake large scale integration (LSI) circuits and their abnormal behavior [20].…”

A new differential magnetic‐field probe with high detection sensitivity for near‐field scanning

“…It is well known that the near-field probe [7,8] is the heart of the near-field scanning system, which determines the measurement capability of the system. In general, these parameters characterizing the probe performance mainly consist of wide bandwidth [9,10], multiple components [11][12][13][14], electric-field suppression ratio [15][16][17][18][19][20][21][22][23], and high sensitivity [24][25][26][27][28]. Among them, a special coaxial via array is often used to obtain the wideband operation by adjusting the inductance and capacitance values of the probe [12], and a pair of orthogonal loops is used to measure two orthogonal magnetic components [13].…”

“…However, these probes have a low detection sensitivity due to the single shorted loop. Therefore, the differential loops, which can sense double electromagnetic signal, are used to improve the detection sensitivity in [18][19][20][21][22][23]. Note that these probes can also have a high electric-field suppression ratio due to the characteristics of the differential and common modes.…”

Asymmetric calibration method on a back‐to‐back double‐loop differential magnetic field probe

“…Near-field measurement is a very important technology for electromagnetic interference analysis [1][2][3][4][5][6]. As a powerful tool for near-field measurement, near-field probes have attracted wide attention [7][8][9][10].…”