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Showing papers by "Jun Fan published in 2019"


Journal ArticleDOI
TL;DR: A new equivalent dipole model hybrid with artificial neural network (ANN) is proposed in this paper for electromagnetic interference (EMI) estimation and a novel source reconstruction solution for the EMI problems is provided.
Abstract: A new equivalent dipole model hybrid with artificial neural network (ANN) is proposed in this paper for electromagnetic interference (EMI) estimation. Equivalent dipole method, based on the free-space Green’s function, is usually used to model unknown EMI sources on printed circuit boards. For high-speed and dense circuits, there may be multi-reflection and/or diffraction between the EMI source and its nearby components. Traditional dipole model usually omits such effects and leads to an inaccurate result in some cases. In our proposed method, the Green’s function of dipole is taken as input and the radiated EMI field is taken as the output of ANN. We use the powerful mapping ability of ANN to modify the matrix–vector multiplication between free-space Green’s function and dipole moments in the traditional dipole model, so that a new mapping between equivalent dipoles and their radiated fields is established. The near field of the EMI source is obtained by planar scanning, and is used for ANN training. After training, the ANN is used to predict the EMI field at the region of interest. Both numerical example and measurement example are given to show the effectiveness of the proposed ANN method. This paper provides a novel source reconstruction solution for the EMI problems.

49 citations


Journal ArticleDOI
TL;DR: Two resonant electric-field probes with improved sensitivity for near-field measurements are proposed and measurements in weak radiated level are conducted to validate the improved sensitivity of the resonant probes.
Abstract: The designs of two resonant electric-field probes with improved sensitivity for near-field measurements are proposed and measurements in weak radiated level are conducted. One probe is the resonant monopole probe and the other is named the resonant T-shaped probe with further improved sensitivity. Each of the two probes is fabricated on four-layer printed circuit board using high-performance and low-loss Rogers material ( $\varepsilon _{ {r}} = 3.48$ and tan $\delta = 0.0037$ ), which consists of an LC resonator made up of a planar spiral stripline (inductor) and a rectangular plate (capacitor), a single-stub transformer, and a SubMiniature version A connector. The LC resonator can achieve a specific resonant frequency for a specific narrowband of interest with the pure input resistance. The single-stub transformer is used to transform the pure input resistance to the input impedance of measurement instruments to acquire maximum transmission power. Compared with the referenced broadband probe with the same physical size of tip, the measured $\vert \text{S}_{ {12}}\vert $ of the resonant monopole probe is enhanced by 9 dB at the resonant frequency. The resonant T-shaped probe proposed has 3.3-dB sensitivity higher than the resonant monopole probe in terms of $\vert \text{S}_{{12}}\vert $ . In order to validate the improved sensitivity of the resonant probes, comparisons on the improvement of sensitivity with other probes are also introduced.

34 citations


Journal ArticleDOI
TL;DR: A series of solutions for improving the standard OTA measurements to meet the IoT OTA requirements and the radiated two-stage (RTS) method is introduced, including the pattern measurement error elimination and the inverse matrix auto-solving.
Abstract: The explosion of applications of Internet of Things (IoT) wireless devices urgently requires over-the-air (OTA) performance evaluations. However, the challenges mainly due to the fact that the ubiquitous IoT device applications have made it necessary for OTA measurements to be operated in accurate, fast, and cost-effective ways. This paper proposes a series of solutions for improving the standard OTA measurements to meet the IoT OTA requirements. For single-input single-output (SISO) terminals, three test techniques are introduced for speeding up their total isotropic sensitivity tests and improving the test accuracy. For IoT multi-input multioutput (MIMO) devices, the radiated two-stage (RTS) method is introduced. The detailed theories are described mathematically, including the pattern measurement error elimination and the inverse matrix auto-solving. The advantages of the RTS on MIMO system diagnosis are outlined. Besides, a smart test system was introduced, which is suitable for a general office building. Both SISO and MIMO can be conducted in this chamber, resulting in great cost saving. Thus, with innovations on hardware and methodologies, the OTA evaluations can be accommodated and helpful for the IoT industry.

32 citations


Journal ArticleDOI
TL;DR: A high-sensitivity resonant probe for capturing tangential LaTeX values is fabricated on a four-layer printed circuit board and the measurements of the passive circuits (microstrip lines and coupled lines) and active circuit module are conducted to validate the resonan probe.
Abstract: In this paper, a high-sensitivity resonant probe for capturing tangential $E$ -field component is fabricated on a four-layer printed circuit board. The resonant probe consists of an improved dipole employed to further enhance sensitivity, a resonator made up of open- and short-circuit stubs achieving specific resonance, and an integrated Marchand balun used to transform the differential-mode voltage to the single-end output and match the instrument port impedance match. Compared with the referenced broadband probe, the relative sensitivity of the proposed resonant probe in terms of $\vert S_{12}\vert $ is enhanced by 13.21 and 14.82 dB for simulation and measurement, respectively. The absolute sensitivity in terms of the noise-equivalent field strength (NEFS) is 26.4 ${\mathrm{ dB}} \mu {\mathrm{ V}} ({\mathrm{ Hz}})^{1/2} $ . The measurements of the passive circuits (microstrip lines and coupled lines) and active circuit module are conducted to validate the resonant probe.

23 citations


Journal ArticleDOI
TL;DR: The theory of the 2×-thru de-embedding is derived and the self-error reduction schemes are introduced to mitigate the de- embedding errors due to non-ideal manufacturing effects that make mode conversion terms non-zero.
Abstract: Because of the simplicity of design and measurement, as well as the accuracy of results, the 2×-thru de-embedding has replaced the traditional de-embedding algorithms such as thru-reflect-line and short-open-load-thru for printed circuit board (PCB) characterization. In this paper, the theory of [$2^{n}$ -port 2×-Thru de-embedding is derived first. The self-error reduction schemes are introduced to mitigate the de-embedding errors due to non-ideal manufacturing effects that make mode conversion terms non-zero. Both the theory and the self-error reduction schemes are fully validated through simulation and measurement cases.

23 citations


Journal ArticleDOI
TL;DR: In this article, a normal electric probe with miniature size and ultrawideband characteristic is proposed, which is fabricated in a four-layer printed circuit board (PCB) with a high-performance dielectric RO4003C and RO4450.
Abstract: A normal electric probe with miniature size and ultrawideband characteristic is proposed in this letter. The probe is fabricated in a four-layer printed circuit board (PCB) with a high-performance dielectric RO4003C and RO4450. The minimum width of the probe is 4 mm, and the length of probe is 48 mm. The probe can be used in compact and complex space like PCB and integrated circuit. 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 12 dB than commercial probe above 1 GHz, and the spatial resolution is 1 mm when the height of probe is 0.3 mm. The proposed probe is verified with simulation in full-wave tool and measurement.

19 citations


Journal ArticleDOI
TL;DR: In this paper, a transfer function based calculation method is proposed to estimate radio frequency interference (RFI) problems, which can clearly decompose the RFI problem into two parts: the noise source and the coupling transfer function to the antenna.
Abstract: A transfer function based calculation method is proposed to estimate radio frequency interference (RFI) problems. The closed-form equations are analytically derived from Maxwell's equations and the reciprocity theorem. The derived equations can clearly decompose the RFI problem into two parts: the noise source and the coupling transfer function to the antenna. Based on derivations, a transfer function concept is proposed to quantify the coupling coefficient from each unit dipole moment to the victim antenna. The transfer functions can be easily obtained from S -parameter measurements. The proposed method is validated through numeric simulations and real cellphone experiments. Engineering insights drawn from the method are also discussed. Overall, the proposed method is accurate, fast, and can provide physical insights for practical designs.

15 citations


Proceedings ArticleDOI
22 Jul 2019
TL;DR: Comparisons and studies present the advantage of this novel methodology using equivalent circuit model for system level power integrity transient analysis and choose specific voltage regulator module model under specific circumstances.
Abstract: The goal of a well-designed power delivery network (PDN) is to deliver desired voltage level from the source to destination, in other words, to minimize voltage noise and errors delivered to chip. This paper provides power integrity engineers a guideline to model PDN agilely in a simplified method and choose specific voltage regulator module model under specific circumstances. These comparisons and studies present the advantage of this novel methodology using equivalent circuit model for system level power integrity transient analysis.

13 citations


Proceedings ArticleDOI
03 Jun 2019
TL;DR: The resulting I-V curve for the PN junction, using the deep learning solver presented in this work, shows a perfect match to the I-v curve obtained using the finite difference method, with the advantage of being 10 times faster at every time step.
Abstract: Simulating the dynamic characteristics of a PN junction at the microscopic level requires solving the Poisson's equation at every time step. Solving at every time step is a necessary but time-consuming process when using the traditional finite difference (FDM) approach. Deep learning is a powerful technique to fit complex functions. In this work, deep learning is utilized to accelerate solving Poisson's equation in a PN junction. The role of the boundary condition is emphasized in the loss function to ensure a better fitting. The resulting I-V curve for the PN junction, using the deep learning solver presented in this work, shows a perfect match to the I-V curve obtained using the finite difference method, with the advantage of being 10 times faster at every time step.

13 citations


Journal ArticleDOI
TL;DR: In this article, the effect of the additional impedance on PIM levels in coaxial connectors is investigated. But the authors focus on the effect on the passive intermodulation (PIM) distortion caused by the loose contact.
Abstract: The mechanism of the passive intermodulation (PIM) distortion caused by the loose contact in coaxial connectors is of great importance in wireless communication systems. This paper focuses on the effect of the additional impedance on PIM levels in coaxial connectors. First, the additional impedance and PIM levels of the loose contact coaxial connectors are measured. Then, the S-parameters and the additional impedance with three different loose contact cases are simulated. Finally, a modified coaxial connector with different values of conductive tapes is designed to verify the additional impedance impacts on the PIM level. It is shown that the increase of the additional impedance of the metal–metal loose contact will lead to the deterioration of PIM levels in the coaxial connector.

13 citations


Journal ArticleDOI
TL;DR: The differential crosstalk is mitigated by using the principle of symmetry on two adjacent differential signal pairs in the BGA and pin field regions by proposing new full pin map patterns and proving the superiority in mitigating both differential far-end and near-end integrated crosStalk noise.
Abstract: Crosstalk noise on the printed circuit board is usually decreased by adding shielding ground (GND). In the trace routing area, the shielding vias are added to isolate the coupling between different traces. In the ball gate array (BGA) and pin field area, assigning more GND pins has demonstrated the effectiveness of crosstalk reduction between signals. However, such design decreases the signal to ground (S:G) ratio dramatically, herein, it is not suitable for applications that require high signal pin density. Unlike the treatment in the conventional methodology, in this paper, the differential crosstalk is mitigated by using the principle of symmetry on two adjacent differential signal pairs in the BGA and pin field regions. New full pin map patterns are proposed and compared with the conventional full pin map patterns. Without sacrificing the S:G ratio, the proposed maps prove the superiority in mitigating both differential far-end and near-end integrated crosstalk noise. To maintain the low crosstalk level in the entire link path, guidance of differential trace routing is provided and demonstrated in the details. All models in this paper satisfy SerDes channel designing and manufacturing requirements.

Proceedings ArticleDOI
01 Jul 2019
TL;DR: In this article, a method of moment (MoM) based current reconstruction technique is used to reconstruct fields in all planes, especially in perpendicular planes, using given scanning information, and two intended radiators (a bowtie and a ring antenna) and one unintended radiator are used to validate the method.
Abstract: Coupling or electromagnetic interference between different components of a complex electronic product is an important challenge for RF designers. Therefore, reconstruction of unknown fields, especially perpendicular to the scanning plane, is an important issue in the design procedure. A Method of Moment (MoM) based current reconstruction technique is used in this work to reconstruct fields in all planes, especially in perpendicular planes, using given scanning information. Two intended radiators (a bowtie and a ring antenna) and one unintended radiator are used to validate the method. To investigate this method’s reaction to noise, all examples have been simulated in a 3D full-wave time domain solver, and white Gaussian noise (SNR =10 dB) is added in a post-processing step. It is shown that this method can accurately predict fields in the direction of given scanning information for any type of source. However, predicted fields in perpendicular planes are only valid for 2D source structures.

Proceedings ArticleDOI
22 Jul 2019
TL;DR: Comparisons of the received pulse responses after the transfer functions show that both methods can improve the causality of the wave propagation term significantly, whereas the analytical solution has better performances and the numerical method has some limitations.
Abstract: Surface roughness of the conductor in transmission lines will introduce extra losses. The recently proposed Huray model is quite accurate for modeling these additional losses by changing R terms in RLGC models. However, only focusing on the loss modeling of the transmission line may lead to causality issues in time domain simulations. In this paper, the causality requirements of the RLGC models are theoretically analyzed firstly. Then, two solutions of the causality problems in Huray model-based transmission line with rough conductors modeling were proposed and compared. One of them is based on the numerical Hilbert transform, and the other one is analytically based on a complex-valued roughness factor. The causalities of those two solutions are validated by a time domain pulse through a transmission line. The results comparisons of the received pulse responses after the transfer functions show that both methods can improve the causality of the wave propagation term significantly, whereas the analytical solution has better performances and the numerical method has some limitations.

Proceedings ArticleDOI
22 Jul 2019
TL;DR: The heatsink RFI problems are analyzed by two methods using reciprocity theorem, which can be characterized in both the source side and the antenna side on a closed 6-surface box.
Abstract: Heatsinks are widely used to dissipate heat in electronic devices. RF emission from heatsinks and ICs can cause radio frequency interference (RFI) issues. The existence of the heatsink affects the coupling from the noise source to the victim antenna. In this paper, the heatsink RFI problems are analyzed by two methods using reciprocity theorem. In the first method, the heatsink effect is combined with the antenna to derive the transfer function. In the second method, the heatsink can be characterized in both the source side and the antenna side on a closed 6-surface box. The physical insights and comparisons of the two RFI estimation methods based on reciprocity theorem will be investigated. The proposed methods will be utilized on a few numeric simulations for validations.

Journal ArticleDOI
TL;DR: This paper proposes a generalized multiple-scattering (GMS) method to evaluate the current distribution on a cable harness with ground connections to a nearby metal surface to compensate the mutual interactions between the cable harness and the rest of the structure.
Abstract: This paper proposes a generalized multiple-scattering (GMS) method to evaluate the current distribution on a cable harness with ground connections to a nearby metal surface. The GMS method is a hybrid method combining the transmission line theory and the method of moments. The GMS method uses the generalized multiconductor transmission line (GMTL) solver for the cable harness part and the mixed-potential integral equation (MPIE) solver for the rest of the structure including the metal surface and the grounding wires. Neither the GMTL nor the MPIE solver alone takes into account the mutual interactions between the cable harness and the rest of the structure. Therefore, an iterative scheme is arranged in the GMS method to compensate the above-mentioned interactions. These interactions occur via not only field couplings, but also current conducting through the grounding points on the cable harness. A numerical test case is provided to benchmark the proposed GMS method.

Journal ArticleDOI
16 Dec 2019-Energies
TL;DR: In this article, a method for adjusting the effective permeability of the ferrite blocks in the standard model, to tune the self-inductance of the coils as well as the coupling coefficient was proposed.
Abstract: The wireless power transfer (WPT) method for electric vehicles (EVs) is becoming more popular, and to ensure the interoperability of WPT systems, the Society of Automotive Engineers (SAE) established the J2954 recommended practice (RP). It includes powering frequency, electrical parameters, specifications, testing procedures, and other contents for EV WPT. Specifically, it describes the ranges of self-inductances of the transmitting coil, the receiving coil, and coupling coefficient (k), as well as the impedance matching values of the WPT system. Following the electrical parameters listed in SAE J2954 RP is crucial to ensure the EV wireless charging system is interoperable. This paper introduces a method for adjusting the effective permeability of the ferrite blocks in the standard model, to tune the self-inductance of the coils as well as the coupling coefficient. To guarantee the given values of the self-inductance of the coil and coupling coefficient matched those in the standard, we slightly modified the air-gap between the ferrite tiles in a specific region. Based on this method, it was possible to successfully tune the self-inductance of the transmitting coil and receiving coil as well as the coupling coefficient. The proposed method was verified by simulation and experimental measurements.

Journal ArticleDOI
TL;DR: In this article, both the differentialmode (DM) and common-mode (CM) electromagnetic interference (EMI) noises below 1MHz from the ac-dc power supply in a LED TV are analyzed and modeled.
Abstract: Critical conduction mode (CRM) boost power factor correction (PFC) converter is widely used in ac–dc power supplies to achieve high power factor. The switching frequency varies in a half-line cycle. In this article, both the differential-mode (DM) and common-mode (CM) electromagnetic interference (EMI) noises below 1 MHz from the ac–dc power supply in a LED TV are analyzed and modeled. The power supply consists of two parts: CRM boost PFC converter and LLC resonant converter. The conducted EMI noise and noise source voltages are measured in the time domain and then converted to the frequency domain via short-time fast Fourier transform (STFFT). Through the joint time-frequency analysis using STFFT, the drain-to-source voltage of the power MOSFET in the PFC converter is identified as the dominant noise source of both CM and DM EMI noises below 1 MHz from the power supply. The EMI current path is different during different periods of a cycle of the line voltage. During most time of a cycle, two diodes of the bridge rectifier are forward biased, and the bridge rectifier can be treated as short circuit. The current paths of DM and CM EMI noises are explained and modeled by a linear equivalent circuit model. Three parasitic capacitances need to be considered to model the CM EMI noise in this device under test. From the circuit model, transfer functions relating DM and CM EMI spectra to noise source voltage spectrum are obtained. The conducted EMI spectra are predicted by multiplying the spectrum of noise source voltage by the transfer functions. The prediction matches with measurement. The effects of parasitic capacitances on CM EMI noise are analyzed by simulation and then validated by measurement. The analysis results can help with EMI design to reduce the CM EMI.

Proceedings ArticleDOI
03 Jun 2019
TL;DR: This paper is trying to analyze which factors have influence on the trace impedance correlation and showing step by step how the agreement can be improved.
Abstract: SI engineers usually build PCB test coupons and perform cross-sectioning and material properties extraction, and then do design optimization. But designing transmission lines on PCB with good analysis to measurement correlation is really challenging. Although there are some systematic approaches which can be applied to a broad range of applications for highspeed digital designs, it is found that in the validation process, there is always several-ohm mismatch in the comparison of TDR impedance between simulated and measurement results. This degrades engineers' confidence about high-speed design. Taking a real case as an example, this paper is trying to analyze which factors have influence on the trace impedance correlation and showing step by step how the agreement can be improved.

Proceedings ArticleDOI
18 Jul 2019
TL;DR: In this article, a rectangular-shape resonators (RSR) structure was proposed to mitigate the far-end crosstalk problem in printed-circuit board (PCB) neighboring routes.
Abstract: With improvement in the speed and frequency of electronic circuits, far-end crosstalk (FEXT) problem in printed-circuit board (PCB) neighboring routes becomes one of most critical factors affecting signal quality. In this paper, the FEXT can be mitigated significantly by inserting rectangular-shape resonators (RSR) structures in the coupled microstrip transmission lines where defected microstrip structures (DMS) are etched on the lines. The frequency domain simulation of HFSS shows that the S 41 of this proposed structure is decreased more than 16dB around 3.2GHz, compared with the traditional signal routing. The time domain simulation of ADS shows that the peak of FEXT voltage of this structure is improved to 89% compared to the traditional signal routing. It has been successfully demonstrated by simulation and comparison with all previous techniques that, this novel technique gives the best optimum low values for the peak voltage of FEXT. Thus, there is a great potential in DDR5, where the requirement of the high density wiring design is even severe.

Journal ArticleDOI
TL;DR: In this paper, a cavity-based partial-element equivalent-circuit (PEEC) formulation was used to model the rectangle via structures and the connection between the rectangle and the plate region was rigorously studied.
Abstract: A parallel-plate pair with complex shared antipad structures was analyzed by decomposing it into rectangular local via structures and the plate pair region by virtual interfaces. The rectangle local via structures and the connections between via structures and the plate pair region were rigorously studied. An innovative cavity-based partial-element equivalent-circuit (PEEC) formulation was used to model the rectangle via structures. With special treatment of the reference in the PEEC equivalent circuits, improved circuits model was achieved and all elements of the circuits had clear physical meanings. Furthermore, by enforcing the continuity of the tangential electric fields at the virtual interfaces, the rectangle local via structures were able to connect to the plate region. The impedance parameters of several kinds of rectangle via structures and the whole parallel-plate pair were obtained using the proposed method, and the accuracy of the results was validated with the finite-element solution from a commercial tool.

Proceedings ArticleDOI
22 Jul 2019
TL;DR: In this article, a hybrid method for physical dipole extraction based on genetic algorithm and linear least square method is proposed, which offers an automatic flow to extract the equivalent dipoles without prior decision of the type, position, orientation and number of dipoles.
Abstract: Infinitesimal electric and magnetic dipoles are widely used as an equivalent radiating source model in far field radiated emissions and near field coupling scenarios. In this paper, a hybrid method for physical dipole extraction based on genetic algorithm and linear least square method is proposed. It offers an automatic flow to extract the equivalent dipoles without prior decision of the type, position, orientation and number of dipoles. Compared with conventional linear least square method, this algorithm can extract physical dipoles which are close to original radiating source and minimize the number of dipoles. Compared with conventional genetic algorithm based method, this method reduces the optimization time and is more robust. This method is validated by both simulation and measurement data, and its advantages are proved. It is applied to modeling of the radiation from a clock buffer chip. The extracted equivalent dipoles are used to estimate the near field coupling from the clock buffer chip to a victim inverted F antenna (IFA) in a practical printed circuit board (PCB) by full wave simulation. The estimation matches well with measurement.

Proceedings ArticleDOI
22 Jul 2019
TL;DR: In this article, commonly-used PCB PDN designs are analyzed and categorized based on inductance contribution from specific portions of the current path, and the inductance components are quantified for different parts of the geometry in different designs.
Abstract: Power Distribution Network (PDN) design is an important part of high-speed digital designs. In order to meet the need of high operation speed and low power voltage supply, the impedance of PDN should be lower than the target impedance of the design requirement. Decoupling capacitors are added on the PCB to lower the PDN impedance. The PCB PDN design is often guided by design rules and experience. In this paper, commonly-used PCB PDN designs are analyzed and categorized based on inductance contribution from specific portions of the current path. Then, the inductance components are quantified for different parts of the geometry in different designs.

Proceedings ArticleDOI
22 Jul 2019
TL;DR: In this paper, the authors provided and validated the hybrid target impedance for the PDN impedance optimization in frequency domain and the physics-based equivalent circuit model with small signal model for voltage response validation in time domain.
Abstract: A well-designed power delivery network (PDN) demands a set of efficient and effective modeling and optimization methodology for the Chip-Package-PCB System. This paper work provided and validated the hybrid target impedance for the PDN impedance optimization in frequency domain and the physics-based equivalent circuit model with small signal model for voltage response validation in time domain. The hybrid target impedance defined with current profile-based discrete and continuous target impedance. Two key impedance points in discrete were identified for on-chip worst case switching scenario and voltage regulator module switching ripple, more points can be added if specific core power switching scenario identified. The continuous impedance points are from the conventional target impedance by voltage ripple to dynamic current change. This hybrid method provides a more effective and convergent way to perform system level decoupling capacitors optimization in frequency domain and to meet voltage specification in time domain, also to avoid overdesigning for cost saving.

Journal ArticleDOI
TL;DR: A revised version of the de-embedding method for on-chip transmission lines is presented, decreasing its sensitivity to measurement noise, as is the standard for characterizing system interconnects.
Abstract: An evaluation is presented on the L –2 L de-embedding method for on-chip transmission lines. The method is analyzed using measurement data from two chips. Results are presented in terms of scattering parameters, as is the standard for characterizing system interconnects. The various challenges associated with on-chip modeling and measurements are discussed. Furthermore, a revised version of the L –2 L method is presented, decreasing its sensitivity to measurement noise. All de-embedding results are compared back to “ideal” simulation models for validation or disproof.

Journal ArticleDOI
TL;DR: The work proves a solution to generate an IM phase and magnitude tunable reference for IM measurement, which also proves that IM can be used to carry some information.
Abstract: In this article, a modular designed intermodulation (IM) modulator based on coherent nonlinearity superposition is demonstrated. A coherent combination network for two nonlinear sources (diodes) is composed, excited by a set of two-tone carriers, and the IM products generated from two diodes are inherently coherent. The designed IM phase and magnitude are synthesized by using two IM signals with different magnitudes. The modulator is achieved by modular design, and the manufacture is simplified by using low IM laminate and normal FR-4 substrate to the section with different IM sensitive levels. The work proves a solution to generate an IM phase and magnitude tunable reference for IM measurement, which also proves that IM can be used to carry some information.

Proceedings ArticleDOI
01 Sep 2019
TL;DR: In this article, the authors performed an emission test for a three-phase motor drive system based on the CISPR 25 component-level testing setup for AM radio frequency band, which is from 530 kHz to 1.8 MHz.
Abstract: In electric vehicles, the pulse width modulation scheme is widely used in three-phase motor drive systems for its high performance. However, the fast switching of semiconductor devices may induce excessively high dv/dt and di/dt, which can cause electromagnetic interference (EMI) issues, making it difficult to satisfy electromagnetic compatibility standards. In this paper, the current conducted emission test for a three-phase motor drive system is performed based on CISPR 25 component-level testing setup for AM radio frequency band, which is from 530 kHz to 1.8 MHz. Under these conditions, common-mode (CM) noise generation mechanisms of the motor drive system are identified through measurements. It is found that the dominant mechanism is the mode conversion from differential mode (DM) switching current of the three-phase PWM inverter to CM current through the cable harness due to the imbalances in the PCB structure and EMI filter network which are at the dc input side of the three-phase inverter. Based on this finding, ground (GND) bridges are added between the digital signal and power GND nets to reduce the CM noise. The GND bridge effect on the reduction of CM noise in AM band is experimentally verified and further studied using circuit simulations.

Journal ArticleDOI
TL;DR: In this paper, a biased Schottky diode is mounted onto the slotted plane of a substrate integrated waveguide (SIW) and it consists of a nonlinear dipole to radiate nonlinear signal to the carrier domain and serve as reference signal.
Abstract: An intermodulation (IM) generator based on substrate integrated waveguide (SIW) is demonstrated. This generator has maximal 80 dB dynamic range with a size that is smaller than 65 mm × 40 mm × 1.5 mm. A biased Schottky diode is mounted onto the slotted plane of SIW and it consists of a nonlinear dipole to radiate nonlinear signal to the carrier domain and serve as reference signal. A polarized slot helps focus the linear carrier wave onto the diode and construct a bias-controlled IM distortion. The experiment proves that this device can generate the IM3 reference ranges from -112 to -32 dBm at 2 × 43 dBm, while its minimum step can reach lesser than 0.5 dB. This proposed device can serve as tunable IM standards in PIM test and calibrate the commercial PIM tester.

Journal ArticleDOI
TL;DR: In this article, the authors proposed a method to identify the interference from different noise sources separately, even when they are radiating at the same time, using the decomposition method based on reciprocity theory.
Abstract: As electronic products become more and more complicated, multiple noise sources very likely interfere with the radio frequency receiver simultaneously. This paper proposes a method to identify the interference from different noise sources separately, even when they are radiating at the same time. This method converts magnetic fields to electric fields by the finite-element method (FEM) and employs the decomposition method based on reciprocity theory. In the proposed method, Huygens's surface will be set up for each source. The tangential magnetic near fields on each Huygens's surface are used to solve tangential electric fields correspondingly by the FEM. Then, the sources are removed but their Huygens's surfaces are kept. The victim structure is excited in this case to get the tangential magnetic fields on Huygens's surfaces. A creative FEM processing procedure is applied to obtain tangential electric fields in this situation. Finally, with these two groups of fields, the interference from each noise source can be estimated separately based on reciprocity theory. This method is validated by a numerical example. It is very helpful for engineers to be able to identify the contribution of the coupling from different sources and further solve the electromagnetic interference issues efficiently.

Proceedings ArticleDOI
22 Jul 2019
TL;DR: The general rules in stack-up arrangement are transformed to equalities and inequalities using mathematical programming techniques and the integer programming solver can solve the stack- up arrangement problem very efficiently for a PCB with 20 layers or more.
Abstract: This paper introduces an integer programming application for PCB stack-up arrangement. The general rules in stack-up arrangement are transformed to equalities and inequalities using mathematical programming techniques. Then the integer programming solver can solve the stack-up arrangement problem very efficiently for a PCB with 20 layers or more.

Proceedings ArticleDOI
Ze Sun1, Nicholas Erickson1, Jingdong Sun1, Ryan From, Jun Fan1 
01 May 2019
TL;DR: In this paper, a finite-element method (FEM) with a non-uniform triangular mesh is used to simulate a GaAs MESFET, and the FEM is validated by comparing results back to those obtained by using the FDM.
Abstract: Particle simulations based on the Boltzmann Transport Equation (BTE) and the Monte Carlo method are a powerful tool for studying semiconductor devices in the nanometer to submicrometer regime. As with most numerical solvers, particle simulations require a mesh to solve for the fields within a semiconductor device. Traditionally, particle simulations use a finite-difference method (FDM) on a mesh with uniform step sizes. This work explores using a finite-element method (FEM) with a non-uniform triangular mesh. The FEM is validated by comparing results back to those obtained by using the FDM, for the simple example of a GaAs MESFET. And the FEM runs ten times faster than the FDM. Aside from electrical aspects of the device, heat flow within the device is also studied using the finite-element approach.