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In a multimodule system, an increase in the number of radiating optical modules will increase the electromagnetic emissions. This article investigates the scaled tendency of the emissions in a router system loaded with hundreds of optical modules. An artificial router mimicking the real system was built to investigate this tendency. A patch antenna array mimics the radiation of the optical modules. It can be excited in in-phase and random-phase configurations. The measurement data verifies the theoretical analysis and the prediction from a statistical method without performing hundreds of different experiments on a real router. Assuming that all radiators are radiating at the same frequency and have similar radiation pattern with random phases, the average of the maximal directivity of the system will saturate if the number of radiators (N) is larger than 14. Furthermore, the average of the maximal electric field radiated will increase following a 10 log10 N (dB) tendency.

A technique for measuring the voltage on a person by combining an overhead mounted electrostatic field sensor with Microsoft Kinect image recognition software and hardware is presented in this paper. The Kinect's built-in skeleton detection method was used to determine the posture, height, and location of a person relative to the position of the field sensor. The voltage is estimated using field strength and geometry information. Two different algorithms are proposed for calculating the human body voltage using field strength data captured by the field sensor and human body coordinates recognized by the Kinect. First, using calibration data, the human body voltage was obtained by charging a person to a known voltage and walking through the field of vision, then a correction was performed to convert the field sensor data into the human body voltage. The second algorithm is based on solving Laplace equation. The human body is modeled by using a superposition of spheroids, and the E-field is solved analytically. Results of the algorithms were compared, with the proposed methodology providing less than a ±15% error margin for the human body voltage over a detection area of 2.0 m × 2.5 m.

An analysis methodology is presented to investigate soft failures in electronic devices. This methodology combines transmission line pulse (TLP) full-wave simulations with system-level and TLP measurements. Information on susceptible parts in the device under test (DUT) and/or soft failure sensitivity of the integrated circuits (ICs) are obtained from the measurements. Then, the TLP current spreading within the printed circuit board (PCB) of the DUT is simulated. The susceptible signals can be determined by comparing the simulated voltages and/or currents at the signal terminations with the measured threshold values. If the simulated voltages and/or currents are higher than the threshold values, the signal is considered susceptible and a soft failure may occur in the DUT. Using the obtained information from simulations and measurements, the root causes of soft failures can be identified. Further, by utilizing full-wave simulations, the design of the product can be modified to reduce the electrostatic discharge (ESD) noise on the susceptible signals, and consequently prevent soft failures. The proposed analysis methodology is applied to a tablet which suffers from soft failure. The root cause of the soft failure is identified, and countermeasures are designed against the ESD-induced soft failure.

To demonstrate the electromagnetic full-wave simulation of a secondary electrostatic discharge (ESD), an ESD generator is modeled in three dimensions (3D) and in contact mode discharging to a non-grounded, metallic ear-mesh of a smartphone. The nonlinear Rompe–Weizel SPICE model computes the arc resistance of the secondary discharge between ungrounded metal and a grounded enclosure. The SPICE model is solved using a circuit simulator, and the 3-D model is solved using the transmission-line matrix time-domain numerical method. Transient cosimulation is a new technique that is used to solve both circuit and 3-D models at the same time. The simulation predicts the coupling from ESD to a victim trace in the smartphone. Measurements performed at several stages validate the simulation results. Using this novel methodology, the user can simulate the secondary discharge in products to predict ESD damage and disruption on a system level.

An important aspect of ensuring the power integrity of a power distribution network (PDN) design is to determine the layout, value, package size, and number of decoupling capacitors. To solve the limitation of the vertical connection of the surface-mounting-type capacitor to the power net area fill, a new concept of a capacitor denoted the Z-directed component (ZDC) is proposed in this paper. There are many applications possible with the ZDC with the first implementation as a decoupling capacitor. The ZDC capacitors can be integrated within the printed circuit board (PCB) substrate directly below the package ball and eliminate the integrated circuit (IC) to decoupling capacitor horizontal distance across the power net area fill. Furthermore, the inductance associated with the vertical current paths on the vias from the IC package to the horizontal power net area fill and similarly for the surface-mounted technology decoupling capacitors is eliminated. Since only the inductance of the ZDC capacitor itself remains, there is the possibility of using far fewer capacitors to achieve a high-frequency target impedance specification. The ZDC is a promising technology that gives the PCB designer the opportunity to integrate low equivalent series inductance decoupling capacitors much closer to the noise source than traditional surface-mount capacitors. In addition, in this paper, a high-order model is introduced for the ZDC capacitor to better understand the high-frequency characteristics of the component and is verified with measurements.

The core difference between the posture assumed for IEC 61000-4-2 human metal discharge and a discharge to a wearable device is the impedance between the charged body and the grounded structure discharged to. Especially for a waist-worn device, a larger portion of the body is close to the grounded structure; thus the geometry forms much lower impedance which will lead to higher currents. Despite the variability for the air discharge, in most cases, the current will be higher than 3.75 A/kV as specified for contact mode electrostatics discharge (ESD) calibration. Even for the most slowly rising discharges having a spark length equal to the value given by Paschen's law, a 10 kV ESD from the waist will surpass 37.5 A for a waist-worn metal part discharged (e.g., to a door frame). Modeling the wearable device discharge provides predictions on the current derivative and the transient field a wearable device is subjected to. Observed failure levels of a wearable electronic device and comparing discharges according to the IEC 61000-4-2 test standard against discharges from the device while wearable showed that the IEC set-up may be insufficient to ensure the robustness of the wearable devices.

In this paper, two new feed network designs for single layer and double layer slotted waveguide array antennas are presented. A microstrip to substrate integrated waveguide transition is applied to the single layer antenna. The aperture coupling mechanism is used in order to find the optimum feed network for double-layer structure and to obtain stable radiation characteristics over the frequency band. The prototypes of the proposed antennas have been fabricated and tested. The measured results were compared very well with the simulation results obtained from CST microwave studio and showed low side lobe level at the center frequency of 11.5 GHz for the low-profile 4-channel slotted waveguide arrays.

In this article, a reconfigurable subwavelength plasmonic nano-antenna with Fano resonance effect is presented based on the dual ring structure. In order to achieve reconfigurable characteristics, the interaction of gold with graphene is studied. SiN substrate with refractive index of 1.98 and gold with Palik optical characteristic modified for metal layer are utilized in the design of the proposed nano-antenna. Simulations are performed by using CST Microwave Studio. The biasing effect on extinction cross section is studied for 0 to 0.8 eV . It is shown that the gap method is useful for exciting the Fano resonance in the dual ring nano-antenna and there is only a plasmonic resonance in the simple dual ring antenna. The proposed nano-antenna is useful for THz medical spectroscopy due to its simple design and the ability to control the second resonance frequency by changing the bias of the graphene.

A new capacitor package and PCB embedding technique is introduced to significantly reduce the system power distribution network impedance at the pads of surface mounted integrated circuits. The capacitor is multi-layer ceramic capacitor (MLCC) that is a right cylindrical shape with via channels in the outer wall along the axis of the part. The capacitor called a Z-Directed component (ZDC) is then pressed into a hole in the PCB. The connections to the component are then made by the copper plating process similar to via hole construction. This new configuration dramatically improves the PDN performance of PCBs with fewer components than the conventional solution with SMD decoupling capacitors.

A system level EMC method is proposed in this paper to predict the electromagnetic interference (EMI) from multiple radiators. The problem under test consists of a large network router with 480 optical modules radiating at 10.3 GHz. The proposed method handles the analysis of this system by using different phased array antenna topologies. Systematic conclusions are presented including the effect of same frequency vs. different frequency of radiating subsystems, the possibility of missing the maximum emission (Emax) during horizontal scan and height scan, and the effect of the radiation pattern for different radiators. The results indicate the existence of a 10 Log N (dB) tendency for the Emax parameter in the case of adding a complex electric field (voltage) and random phase distribution over the line cards. It also shows similarity to an 8 Log N (dB) tendency for adding power intensity for different line cards with slightly offset frequencies. The developed method can be extended to other frequency ranges when necessary. The proposed statistical method is useful when it is not practical to assemble a complete system consisting of several radiating subsystems with different frequencies in EMI testing.

Electrostatic discharges (ESD) to parts of a system can lead to system-level soft-failures. These failures can depend on the activity of the system at the moment of discharge. This paper investigates ESD susceptibility as a function of different operating conditions such as software loading, clock frequency, and VDD voltage. Due to the large number of possible conditions, a commercial automated ESD scanner is modified and used to obtain ESD susceptibility maps for each operating condition. The core processor of a single-board computer is selected as the device under test. It is observed that the processor becomes more sensitive to ESD events as its software loading increases. The effect of VDD voltage and clock frequency on the sensitivity of the processor is also discussed. Moreover, the effect of increasing the power distribution network impedance and noise is investigated, partially leading to counterintuitive results.

Transient electromagnetic co-simulation is used to simulate the currents in a discharging rod. The simulation model simultaneously solves Maxwell's equation and the arc resistance equations in time domain to estimate the currents and fields for a given geometry, charge voltage and arc length. The Rompe-Weizel model is used to obtain the time dependent arc resistance, and results from different simulation methods are compared to measured data.

An adjustable spark gap structure is designed to generate Secondary ESD. The primary and the secondary discharge current are directly measured. The setup is modelled using CST full-wave simulation software. The goal is to predict secondary ESD induced current levels using simulation methods, to assist designers in product development in the early design stage.

Motivated by understanding the ESD-induced currents from body-worn, wire and hose connected medical equipment is exposed to, a computer simulation is presented to estimate the impedance of a human body relative to ground. This 3D model is the basis for transient field calculation. A Method of Moments (MoM) frequency domain solution is transformed into time domain via IFFT for further circuit level time domain simulations. The human body is modeled as a homogeneous dielectric with frequency-dependent complex permittivity. Dependence of the impedance on the position of discharge and posture of the human body is investigated. The simulation results are compared with measurements and demonstrate capturing of general tendencies of measured curves.

Correlation between near-field EMI scan and ESD susceptibility scan of a cellphone CPU IC is investigated. It is shown that the ESD susceptibility of the CPU IC depends on the activity of the IC. Based on the obtained correlation between these two scans, it is sufficient to perform the ESD susceptibility scan only by running the application which highly loads the CPU. This reduces the ESD susceptibility measurement time as well as the probability of physical damage to the IC.

A new approach based on hybrid volume-surface integral equation (VSIE) formulation in combination with spherical dyadic Green's function (DGF) is presented in this paper to analyze aperture-coupled multilayer hemispherical dielectric resonator antennas (DRA) with conformal conducting patches. Hybrid VSIE is used for the planar part of the structure and is solved with the aid of spatial-domain method of moments (MoM) in order to compute magnetic surface current in a slot cut in a finite planar perfect electric conductor (PEC) sheet. Multilayer spherical electromagnetic DGFs are used to compute loading effects of hemispherical dielectric resonators and conformal patches on antenna characteristics. The effects of variation in some parameters of the structure on the return loss of the antenna are studied. Accuracy of the presented method is validated by comparing the results obtained from the proposed method with those of CAD simulations.

The theory and experiment of a probe-fed conformal antenna with a conducting parasitic element mounted on a spherical multilayer structure are presented in this article. Linear Rao–Wilton–Glisson triangular basis functions are applied in a mixed-potential integral equation formulation. Current distributions on coaxial probe and conformal radiating elements are computed by using the proper spatial domain electrical dyadic Green's function and its asymptotic approximation. A prototype of such an antenna is fabricated and tested. The effect of the parasitic element on the input impedance, gain, and radiation patterns of the antenna is investigated. It is shown that the antenna characteristics are improved significantly with the presence of the stack. Good agreement is achieved between the results obtained from the proposed methods and measurement results.

Rigorous mathematical method of moments (MoM) for analyzing spherical microstrip aperture-coupled antennas is presented in this paper by using dyadic Green's functions (DGF) in conjunction with magnetic field integral equation (MFIE) and electric field integral equation (EFIE) formulations. With the aid of linear Rao-Wilton-Glisson (RWG) triangular basis functions, spherical three-layer aperture-coupled patch antennas are analyzed. The effect of mutual coupling between slot and patch antenna is developed and the input impedance and radiation patterns of such an antenna are presented. A prototype of a spherical aperture-coupled antenna is fabricated and tested. The measurement results are compared to the results of the proposed method and a good agreement between the results is achieved. The measured efficiency and gain of this antenna at 3.15 GHz are 85% and 5.23 dB, respectively.

In this paper, a new simple VHF-LB vest antenna is proposed, simulated, fabricated and tested. The simulation results for various user's positions such as standing, kneeling and prone on the ground are obtained and compared with conventional whip antenna mounted on mobile unit. It is shown that the proposed antenna outperforms the whip antenna in terms of gain and body energy absorption. The measurements results of proposed vest antenna confirm the simulation results.

Theory and experiment of a spherical probe-fed conformal antenna with a parasitic element mounted on a spherical multilayer structure are presented in this paper. Linear Rao-Wilton-Glisson (RWG) triangular basis functions are applied in MPIE formulation. Current distributions on coaxial probe and conformal radiating elements are computed by using spatial domain Dyadic Green's Function (DGF) and its asymptotic approximation. A prototype of such an antenna is fabricated and tested. The effect of the parasitic element on the input impedance and radiation patterns of the antenna is investigated. It is shown that the antenna characteristics are improved significantly with the presence of the conducting parasitic element. Good agreement is achieved between the results obtained from the proposed methods and the measurement results.

A single-cell tri-band composite right/left-handed (CRLH) resonant antenna is presented. The antenna is designed on a single-layer coplanar waveguide-fed based on the T-junction discontinuity equivalent circuit. The proposed antenna provides compact size, easy fabrication process, multi-band feature and higher efficiency in comparison with the previously reported CRLH resonant antennas. The single-cell CRLH resonant antenna is fabricated and the measurements are consistent with the simulation result.

In this paper we propose a novel efficient modulation technique with low probability of error in large M. spiral constellation shift keying (SCSK) is our suggestion for this purpose.