A normal component electric probe with miniature size and ultrawideband characteristic is proposed in this paper. The probe is fabricated in a four-layer printed circuit board (PCB) with high performance dielectric RO4003C and RO4450. The minimum width of the probe is 4mm and the length of probe is 48mm. The probe can be used in compact and complex space like PCB and integrated circuit (IC). The designs of U-shaped structure and tuning element matrix are used to expand the work band and optimize the impedance of signal via. The work band of probe can cover from 9 kHz to 40 GHz. It can improve the test efficiency in ultrawideband application compared with series probe. The sensitivity of the probe is higher about 12dB than commercial probe above 1GHz, and the spatial resolution is 1mm when the height of probe is 0.3mm. The proposed probe is verified with simulation in full wave tool and measurement.

A noncontact active electric field probe with miniature size and high sensitivity is designed for the noise location in electronic systems from 9 kHz to 1 GHz. This probe is fabricated in a multi-layer printed circuit board (PCB) (dielectric constant of 4.2 and loss tangent of 0.02). The minimum width of the probe is 4 mm and the length of it is 48 mm which allows it to be used in compact and complex space like the PCB and the integrated circuit (IC). The dual-stage amplifier circuit and the door-shaped structure are applied to the probe design, which improves the transfer gain of the probe 40 dB – 50 dB higher than that of an equivalently sized passive electric field probe. The spatial resolution is 0.6 mm while the height of the probe tip above the device under the test (DUT) is 0.3 mm. The proposed probe is verified with three-dimensional electromagnetic simulation and near-field measurement.

This paper presents a novel tangential electric-field sensor with an embedded integrated balun for sensing up a tangential electric field over a circuit surface in the near-field measurements covering the GPS band. The integrated balun is embedded into the sensor to transform the differential voltage induced by the electric dipole into the single output voltage. The measurement system with a high mechanical resolution for the characterizations and tests of the sensor is detailed in this paper. The frequency response of the sensor characterized by a microstrip line from 1.35 GHz to 1.85 GHz (covering the GPS band) is rather flat. The rejection to the magnetic field of the sensor is up to 20.1 dB. The applications and validations of the sensor are conducted through passive/active circuit measurements.

A method of moment (MoM)-based current reconstruction method is proposed to estimate the surface current density on the ground plane. Current continuity property is automatically enforced with Rao-Wilton-Glisson basis function. Both the least square method and the optimization method are utilized to solve the inverse problem and obtain the ground current. The proposed optimization method is successfully validated with numeric simulations and also a real-world measurement example. The reconstructed current distribution on the ground plane is further used in a typical radio frequency interference (RFI) example to perform RFI estimation and provide guidelines for RFI design. The proposed MoM-based ground current reconstruction method can be valuable to estimate and debug RFI issues in early design stage.

A simplified physical-based model for deep-snapback transient voltage suppressors (TVS) is developed in this article. While based on physics, the number of parameters and components is minimized, so the model can be tuned easily from available measurements of the packaged TVS. SPICE convergence issues seen in previous snapback device models are eliminated by adding nonlinear damping components to the model. No convergence issues were seen among any of the simulations performed for this study, which includes transmission-line pulse tests with multiple levels and rise times. The proposed model was used to represent two different TVS devices and was validated in both device- and system-level simulations. Simulations of quasi-static and transient behavior matched measurement results within about 20% among all the tested cases.

Equivalent sources found from near-electric and magnetic field scans are often used to predict and solve interference problems. While there are many ways to represent the source, the user lacks the ability to determine which of the many possible source configurations is more likely to represent the “true” source, and thus accurately represent field data outside the measurement area and in the presence of typical measurement errors. A methodology is proposed for estimating which of many possible dipole source representations of near-field scan data are likely to give better estimates of fields outside the measurement scan plane when utilizing imperfect measurement data. A quality metric for determining better configurations is proposed, which utilizes the statistical variation of the global difference measure (GDM) in the predicted and measured fields. Equivalent sources are estimated when adding noise to measurement data, and prediction statistics are generated for multiple instantiations of measured noise. Results demonstrate that the better configurations minimize the average plus standard deviation of the GDM. The ability of the technique to identify robust source configurations was tested when measurements were subject to additive measurement noise, cross-field coupling, and systematic errors in probe position, and was evaluated based on its ability to predict fields at points above and to the side of the measurement plane. The method consistently identified better source configurations using both simulated and measured data.