Showing papers by "Jun Fan published in 2017"
TL;DR: Several key technologies that could be widely used in the 5G OTA measurements are discussed, including near-field to far-field transformation, anechoic chamber absorbers, and sampling antennas.
Abstract: Over-the-air (OTA) measurements are the standardized methods to evaluate radio performance in wireless systems EMC issues such as interference and receiver desensitization are important factors In this paper, OTA measurement challenges in the upcoming fiftth generation (5G) wireless systems are overviewed Several key technologies that could be widely used in the 5G OTA measurements are discussed, including near-field to far-field transformation, anechoic chamber absorbers, and sampling antennas The most important devices under test (DUT) for 5G OTA are chip sets, user equipment, and active array systems The OTA test challenges for certification, research and development, and mass production for these DUTs are introduced
90 citations
TL;DR: The ground vias, called via fence, are utilized to suppress the resonance caused by the parallel-plate mode of conductor-backed coplanar waveguide (CB-CPW), expanding the working frequency band.
Abstract: In this paper, a miniature electric field probe with an ultrawideband of 9 kHz–20 GHz is proposed, fabricated, and tested. The electric field probe is fabricated on a four-layer printed circuit board using high-performance and low-loss Rogers material ( $\varepsilon _{\mathrm{r}}= 3.48$ and tan $\delta = 0.0037$ ). Coax-thru-hole via array is used to control the signal via impedance to achieve impedance $50~\Omega $ match over the whole working band, reducing the harmful influence on the probe’s characteristic. The ground vias, called via fence, are utilized to suppress the resonance caused by the parallel-plate mode of conductor-backed coplanar waveguide (CB-CPW), expanding the working frequency band. Experimental result shows $\vert S_{21}\vert $ rather smooth in operation band, demonstrating the working frequency band is up to 9 kHz–20 GHz. The electric field probe has a 2–3 mm spatial resolution, which has a good ability to locate the interference source.
52 citations
TL;DR: In this paper, a fast and accurate algorithm that can model the emissions from ICs by generating a set of equivalent dipole elements was proposed, which only requires the information of the field magnitudes on two near-field scanning planes of different heights.
Abstract: Near-field scanning with phase measurement is always a challenge in practical experiments because of its complexity and lack of accuracy. Therefore, utilizing the magnitude-only information to achieve phase-retrieval and emissions source reconstruction is preferred. This paper proposes a fast and accurate algorithm that can model the emissions from ICs by generating a set of equivalent dipole elements. The process of this algorithm only requires the information of the field magnitudes on two near-field scanning planes of different heights. Unlike other conventional source reconstruction techniques (such as genetic algorithm, gradient optimization), the proposed approach iteratively performs the back-and-forth transformations among the fields and equivalent dipole elements. By optimizing the locations of the equivalent dipole array and the initial values of these dipole elements, the iteration process is capable of quickly converging to the correct electromagnetic field values, including both magnitude and phase. The fields recovered from the calculated equivalent dipole sources have been validated by comparing to the fields emitted from a practical IC source.
45 citations
TL;DR: In this article, the characteristic mode analysis has been implemented together with the integral equation based numerical methods to identify the hot spots for EMI radiation, where the radiated power from each part of the structure can be quantified using the radiating current.
Abstract: Radiation is a vital mechanism affecting electromagnetic interference (EMI), noise control, and performance optimization in today's electronic designs. Due to tight electromagnetic compatibility standards, it becomes increasingly important to diagnosis the radiation hot spot in the radiation process before the mitigation is applied. In this paper, the characteristic mode analysis has been implemented together with the integral equation based numerical methods to identify the hot spots for EMI radiation. During this process, the current is split into radiating and nonradiating ones. The radiated power from each part of the structure can be quantified using the radiating current. Therefore, the radiation hot spot can be identified. Several numerical examples are applied to benchmark the proposed approach. This paper provides a guideline in discovering radiation related geometrical features, and designing methodologies for real geometries.
29 citations
TL;DR: Based on the electrical properties of fabricated transmission lines, the improved Root-Omega method applied to cases with smooth and rough conductors is validated using simulations in this article, and the error sensitivity is significantly reduced by the proposed improvements.
Abstract: Electrical properties of dielectric substrate are critical in designing high-speed products in terms of signal and power integrity. It is important to accurately characterize the dielectric properties to avoid overestimating or underestimating in the design. This paper proposes the improved “Root-Omega” method for extracting dielectric properties from fabricated multilayer printed circuit boards. Based on the electrical properties of fabricated transmission lines, the improved “Root-Omega” method applied to cases with smooth and rough conductors is validated using simulations. Error sensitivity analysis is performed to demonstrate the potential errors in the original “Root-Omega” procedure and the error sensitivity is significantly reduced by the proposed improvements.
24 citations
TL;DR: In this article, the authors analyzed the impact of characteristic impedance variations among standards on the accuracy of the thru-reflect-line (TRL) calibration technique and derived the expressions of the calibration coefficient errors due to the manufacturing tolerances.
Abstract: In this paper, we analyze the impact of characteristic impedance variations among standards on the accuracy of the thru-reflect-line (TRL) calibration technique. The impedance transformer method is adopted to derive the expressions of the calibration coefficient errors due to the manufacturing tolerances. It is found that three factors can affect the magnitude of the errors in the calibration coefficients (c/a and b terms), which are crucial to get the final calibrated results. The first factor is related to the original parameters of the error networks (test fixtures): the larger the insertion losses, the smaller the error in b ; the error in c/a may see an opposite trend if the error network is lossy instead of lossless. The second factor is denoted as the phase contribution (one of the three multipliers of the derived error expression): the magnitude of this error contributing item is approximately equal to the ratio of two hyperbolic sine functions, the variables of which are the length of Line and the length difference between Line and Thru, respectively. The third factor comes from the impedance differences between Thru and Line: the smaller the impedance variation, the smaller the error. The error analysis, presented here, can help engineers evaluate the calibration accuracy by analyzing the error contributing items. It also can be further used to guide test fixture designs to maximize TRL's error immunity to the transmission line characteristic impedance variations.
23 citations
01 Aug 2017
TL;DR: In this paper, a method of moment (MoM) based current reconstruction method is proposed to estimate the current on the ground plane, which requires phased resolved near field data for accurate current reconstruction.
Abstract: Multiple digital ICs sharing ground plane have potential problems of ground noise interference to each other. Current distribution on the ground plane can introduce intra-system EMC issues, which can possibly result in receiver desensitization issue in wireless devices. In this paper, a method of moment (MoM) based current reconstruction method is proposed to estimate the current on the ground plane. This method requires phased resolved near field data for accurate current reconstruction. The proposed method is validated by a numerical example. The current reconstructed from the proposed method is compared with the current from the simulation tool. The difference is within 3.5 dB which is acceptable for most engineering practice.
22 citations
TL;DR: In this article, a physics-based model size reduction (PMSR) method is applied to get the equivalent circuit model for the above-ground geometries, which can be used in analyzing the structure in its parts.
Abstract: Proper power integrity (PI) analysis is required for printed circuit board (PCB) power distribution network (PDN) design. Top-layer interconnect inductance for PI has always been a vital concern for high-speed industry. Developing a simple physics-based equivalent circuit model for critical structures is essential for understanding the physics of the system and for intelligent designs. In this paper, a physics-based model size reduction (PMSR) method is applied to get the equivalent circuit model for the above-ground geometries. The extracted physics-based models are also based on the partial element equivalent circuit (PEEC) method, and can be used in analyzing the structure in its parts. By applying PMSR method, a physics-based equivalent circuit model can be proposed and this circuit model is related to the geometric features of the design. In this way, PMSR method can provide an intuitive guideline in designing PCB and reducing above inductances, therefore, a low-ripple dc voltage can be delivered through PDN. Taking advantage of PEEC and PMSR methods, the top-layer inductances of three different geometries are calculated and the physics-based circuit models are obtained, respectively.
20 citations
01 Aug 2017
TL;DR: An error bound analysis is performed for 2x thru de-embedding methods: AFR (Automatic Fixture Removal) and SFD (Smart Fixture De- embedding).
Abstract: In this paper, an error bound analysis is performed for 2x thru de-embedding methods: AFR (Automatic Fixture Removal) and SFD (Smart Fixture De-embedding). Basically, a certain amount of error is assumed to exist in S11 of 1x. This error will cause the de-embedded results to vary within a certain range. The upper bound and lower bound of the magnitude of the de-embedded results are given.
20 citations
01 Aug 2017
TL;DR: An analytical model of power supply noise induced jitter (PSIJ) at inverter chains is proposed in this paper based on the piecewise linear approximated I-V curve model, closed-form equations of PSIJ transfer function at a single inverter are derived.
Abstract: An analytical model of power supply noise induced jitter (PSIJ) at inverter chains is proposed. Based on the piecewise linear approximated I-V curve model, closed-form equations of PSIJ transfer function at a single inverter are derived. The PSIJ transfer function of an inverter chain output is then obtained by linearly stacking the single inverter-PSIJ transfer functions. Accuracy of the proposed analytical model is successfully validated by SPICE simulations. In addition, characteristics of the PSIJ transfer function at inverter chains are discussed.
19 citations
TL;DR: In this article, a method based on a hybrid of transmission-line and surface MoM was proposed to calculate interactions between thin wire structures such as cable harness and conductive surfaces, such as vehicle body.
Abstract: Interactions between cable harness and vehicle body can be calculated using the full-wave method-of-moments (MoM) formulation. Although the full-wave MoM formulation can help us to calculate these interactions with great accuracy, it can be fairly time consuming when dealing with complex wire structures. On the other hand, the conventional multiconductor transmission-line theory can be used to obtain a simple model of the interactions, but only the effect of the transmission-line (TL)-mode current can be accounted for in this method. Starting with the complete electrical field integral equations, the current on a two-conductor thin wire structure due to incident field illumination can be decomposed into TL and antenna modes. Both modes can be solved using a SPICE solver in the form of Telegrapher's equations. A proposed multiple scattering (MS) method based on a hybrid of TL and surface MoM can then be used to calculate interactions between thin wire structures, such as cable harness, and conductive surfaces, such as vehicle body. A test case shows that wire current computation using the proposed MS method takes less time but reaches the same accuracy compared to the full-wave MoM.
TL;DR: In this article, a lumped circuit model is used to develop a well-defined relation between the design geometry, the model elements, and the PDN impedance response features, which are then mapped to model elements using sensitivity analysis and consequently to design geometry.
Abstract: Power distribution network (PDN) design in high speed digital systems is a critical challenge for system performance. Common design methodologies refer to guidelines and engineering best practices while using simulations to evaluate the design. If the relation between the design choices and the performance parameters is known, the engineering is simpler. A lumped circuit model that relates physics and design geometry was proposed in an earlier study for modeling practical printed circuit board (PCB) PDN designs. In this paper, the lumped circuit model proposed earlier is used to develop a well-defined relation between the design geometry, the model elements, and the PDN impedance response features. The PDN impedance is simplified and broken down into common features for all PCB PDNs. These features are mapped to the model elements using sensitivity analysis and consequently to design geometry. The physics behind the relation between the response and geometry is reinforced with the current paths in different frequency ranges and generalized to common PDN designs on multilayer PCBs that use area fills for the power net.
TL;DR: The polynomial-chaos method and the response surface method are adopted to mathematically model the variability of crosstalk and the two methods are compared in terms of mathematical theories, sampling schemes, postprocessing, accuracy, efficiency, and limitations.
Abstract: The variability of crosstalk due to changes in differential and ground via configurations is studied in this paper. The polynomial-chaos method and the response surface method are adopted to mathematically model the variability. One goal of the work is to exploit the obtained models to locate the optimal response that both meets the performance requirement and remains robust to geometry variations due to manufacturing tolerances. Both methods correlate well with simulations and show great capabilities in practical applications for optimization and sensitivity analysis. The other goal of the work is to compare the two methods in terms of mathematical theories, sampling schemes, postprocessing, accuracy, efficiency, and limitations. Details of the comparison is given through this paper and a summary table is included in Section V .
TL;DR: In this article, a lumped circuit model was built using admittance blocks extracted from a mixedpotential integral equation (MPIE) formulation to simplify coupling analysis for cables going through a cable tray.
Abstract: The China high-speed trains use cable trays to neatly arrange the cables running through the distributed systems. On one hand, they protect cables against external electromagnetic interference and reduce external radiation from the cables. On the other hand, the cable trays create waveguide structures that affect the coupling among cables inside the cable trays. To simplify coupling analysis for cables going through a cable tray, a lumped circuit model was built using admittance blocks extracted from a mixed-potential integral equation (MPIE) formulation. In the MPIE formulation, either the half-free space or the waveguide dyadic Green's function was used depending on the region where the cables were. A test case was investigated. Results by the proposed circuit model were validated by measurement and full-wave simulation results.
01 Aug 2017
TL;DR: In this article, the authors focus on transmitter coil design to maximize the quality factor (Q-factor) in both 100 MHz and 6.78 MHz, and propose an optimal coil winding method to maximize Q-factor.
Abstract: Coil design is one of the critical part to get high power transfer efficiency for wireless power transfer (WPT) system. There exists coil figure of merit (FOM), which is used to evaluate coil design in the aspect of WPT system efficiency. WPT coil FOM is function of coil quality factor (Q-factor) and coupling coefficient, k and higher Q and k guarantees higher coil-to-coil efficiency. Coil DC loss, skin effect, proximity effect, and displacement current between turns are key factors to determine Q-factor and its effects changes depending on wire-type, winding method, and target frequency. In this paper, we focus on transmitter coil design to maximize Q-factor in both 100 MHz and 6.78 MHz. Coil Q-factor equations are provided to explain and analyze the physics and measurement was done for the validation of the equation. Finally optimal coil winding methods are proposed to maximize coil Q-factor
TL;DR: In this article, the authors proposed a hybrid equivalent source model for radiation problems in integrated circuits (ICs), which is based on two sets of equivalent dipoles, one is converted directly from the current/voltage information distributed along the IC package, while the other initially is solved from linear equations that describe the relationship between the dipoles and scanned fields.
Abstract: An efficient emission model for radiation problems in integrated circuits (ICs) is required at the early phase of industrial design. Traditional source-reconstruction methods rely exclusively on near-field scanning and lack the flexibility needed to handle varying IC work conditions. The proposed hybrid model can build a physical connection to the IC's inherent electric properties; therefore, after simple parameter adjustments, it can be applied to any mode of operation. The complete model consists of two sets of equivalent dipoles; one is converted directly from the current/voltage information distributed along the IC package, while the other initially is solved from linear equations that describe the relationship between the dipoles and scanned fields. Then, they are multiplied by a scaling factor to adapt to varying IC work conditions. The emission behavior of an 8-bit commercial microcontroller was reasonably simulated in full-wave solver under various working conditions. The proposed hybrid equivalent source model correctly predicted the simulated reference fields at each operation mode. The feasibility and flexibility of the proposed modeling method have been well validated.
TL;DR: In this article, the authors proposed a new objective total isotropic sensitivity (TIS) measurement method, where the measured TIS is a function of the transmitter power level at its thermally stable condition.
Abstract: The characterization of the performance of wireless devices plays a significant role in developing radio products that meet the demands of the latest standards and deliver a satisfying user experience. With current standard total isotropic sensitivity (TIS) measurement, the transmitters are set to work at their maximum transmission power level. However, the standard TIS test procedure is unable to accurately reflect a receiver's performance because in actual usage transmitters are rarely working at their maximum power level. In measurements, different kinds of devices hold different maximum power levels. The measured radio sensitivity depends on the instantaneous local temperature of the radio, and the local temperature depends on the heat generation (power levels), the heat dissipation, and time. So the power levels and the thermal conditions could affect their radio sensitivity and, hence, the TIS. With standard TIS methods, the maximum power level and the radio's thermal condition cause ambiguity in the measurements. However, this paper proposes a new objective TIS method. With this new TIS method, the measured TIS is a function of the transmitter power level at its thermally stable condition. The proposed method resolves the ambiguity of the TIS measurement.
01 Aug 2017
TL;DR: This paper aims on building a generic parameterized and SPICE-compatible circuit model for designing differential via in a frequency range up to 40GHz.
Abstract: This paper presents a survey on physics-based modeling strategies for differential via in high-speed multilayer printed circuits (PCBs). Driven by the goals of accurate and efficient design, researchers have explored several approaches for differential via modeling, include π-type RLC circuit, differential transmission line with via-plate capacitance/effective dielectric constant and parallel plate impedance model. This survey provides overviews of these modeling strategies and comparisons by correlating mixed-mode S-parameter from HFSS. In particular, this paper then aims on building a generic parameterized and SPICE-compatible circuit model for designing differential via in a frequency range up to 40GHz.
01 Aug 2017
TL;DR: In this paper, the authors applied integral-equation (IE) based method and characteristic mode (CM) analysis to split the current into radiating and non-radiating ones.
Abstract: Electromagnetic radiation for a printed circuit board (PCB) midplane connector is studied in this paper. By applying integral-equation (IE) based method and characteristic mode (CM) analysis, the current is split into radiating and non-radiating ones. The radiated power from each part of the structure can be quantified using the radiating current. Therefore, the radiation hot spot can be identified for both edge-side coupled and broad-side coupled connectors. Furthermore, the radiation characteristics for these connectors are compared.
TL;DR: The algorithm was developed in such a way that the equivalent capacitance model can be implemented into standard circuit simulators and a comparison with a known procedure based on the genetic algorithm approach is offered as validation.
Abstract: This paper explains the extraction from the measurement of the parameters necessary in time domain to identify the hysteretic behavior of the coupling capacitance of through silicon vias (TSVs). The algorithm was developed in such a way that the equivalent capacitance model can be implemented into standard circuit simulators. A comparison with a known procedure based on the genetic algorithm approach is offered as validation. Results showing the robustness of the algorithm and the effects of the hysteresis on the crosstalk among TSV and integrated circuit active devices are reported and discussed.
TL;DR: In this paper, a meander line internal antenna used for wireless terminal is proposed, where the current of this antenna is mostly distributed on the antenna radiator itself, rather than on the main board of the wireless device.
Abstract: In this paper, a meander line internal antenna used for wireless terminal is proposed. The current of this antenna is mostly distributed on the antenna radiator itself, rather than on the main board of the wireless device. As a result, the chance of having intrasystem electromagnetic compatibility issues, which usually result in receiver desensitization in wireless radios, can be significantly reduced. The antenna has good radiation performance in the vertical polarization with a low physical profile, compared to the existing antenna designs for typical wireless terminals. The antenna has efficiency similar to the monopole antenna with much less reference/ground plane dependence, which is important for high sensitivity radio design. Further, the mutual coupling (i.e., isolation) between the two such antennas is studied and the envelope correlation coefficient between the two such antennas when they are placed in one system is found to be low, which is important for better throughput for a multiple input and multiple output system. Both simulation and measurement results demonstrate the proposed design.
01 Oct 2017
TL;DR: In this article, a generalized characteristic mode analysis for lossy material and/or with resistive loads is developed for practical structures, by applying integral-equation (IE) based method and characteristic mode (CM) analysis, the current is split into radiating and non-radiating ones.
Abstract: Characteristic mode analysis has been proposed for lossless case for decades. However, for real electromagnetic interference (EMI) structures, such as printed circuit board (PCB) midplane connector and heat sink, lossy material (such as copper) and terminations (resistive loads) are unavoidable which tradidiotnal CM method cannot handle. In this paper, a generalized CM analysis for lossy material and/or with resistive loads is developed for practical structures. With the proposed method, by applying integral-equation (IE) based method and characteristic mode (CM) analysis, the current is split into radiating and non-radiating ones. The radiated power from each part of the structure can be quantified using the radiating current. Therefore, the radiation hot spot can be identified. This method facilitates the CM method in real applications.
20 Jun 2017
TL;DR: In this article, a method to predict the modulated noise coupling to an antenna is proposed and experimentally validated using a practical mobile phone, where the baseband noise of a liquid crystal display (LCD) is modulated with the Tx carrier signal of cellular communication, resulting in a radio frequency desensitization problem.
Abstract: A method to predict the modulated noise coupling to an antenna is proposed and experimentally validated using a practical mobile phone. The baseband noise of a liquid crystal display (LCD) is modulated with the Tx carrier signal of cellular communication, resulting in a radio frequency desensitization problem. The modulation mechanism is understood and its circuit representation is proposed to estimate the modulated noise coupling to an antenna. The modulation coefficient, which represents a relationship between the coupled voltage and modulated current, is experimentally extracted from a stand-alone LCD panel. The proposed modulation model is successfully validated through comparison with measurements using a practical mobile phone.
01 Aug 2017
TL;DR: In this article, the authors proposed a radiated two-stage based method for the multiple input multiple output (MIMO) system evaluations, where not only the final throughput values, but also the antenna patterns, the antennas' envelope correlation coefficient, the antenna imbalance and the radiated sensitivity of the MIMO device can be obtained over the air.
Abstract: This paper proposed a radiated two-stage based method for the Multiple Input Multiple Output (MIMO) system evaluations. By using the proposed method, not only the final throughput values, but also the antenna patterns, the antennas' envelope correlation coefficient, the antennas' imbalance and the radiated sensitivity of the MIMO device can be obtained over the air. Moreover, through these parameters, the antenna performance and the radio frequency circuit performance can be investigated individually, which is significant for engineers to find out the imperfections and to improve the design qualities. All in all, this method is valuable for research and development for MIMO devices.
01 Aug 2017
TL;DR: In this article, a differential ICN analysis is performed for several configurations of package-to-PCB transitions using the design of experiment (DoE) statistical method, and a guide line is proposed to maintain the tradeoff among the differential ICNs, design space, and manufacturing cost.
Abstract: The integrated crosstalk noise (ICN) has been wildly used as an alternative to the insertion crosstalk ratio (ICR) for channel crosstalk evaluation in the IEEE 802.3ba standard. In this work, a differential ICN analysis is performed for several configurations of package-to-PCB transitions. Using the design of experiment (DoE) statistical method, differential ICN is quickly estimated for various input factors such as pin mapping, physical dimensions, and level of shielding. Optimization guide line is proposed to maintain the tradeoff among the differential ICN, design space, and manufacturing cost.
01 Aug 2017
TL;DR: In this paper, the analytical equation of via-plane capacitance for separated-antipad via structure is extended to the shared-antiphase via structure case, by using the equivalent area of antipad and ratio revision method.
Abstract: Shared-antipad via structure is commonly used for high-speed printed circuit board (PCB) design. Therefore, an accurate via-plane capacitance evaluation for this kind of geometry is critical to facilitate engineering design. In this paper, the analytical equation of via-plane capacitance for separated-antipad via structure is extended to the shared-antipad via structure case, by using the equivalent area of antipad and ratio revision method. The proposed method is validated with numerical methods in HFSS for a typical structure widely used in practical high-speed PCB design.
TL;DR: In this paper, a liquid crystal display baseband noise, whose spectrum is much lower than RF bands, is modulated with the carrier signal of cellular communication and interferes with an Rx receiver resulting in a desensitization problem.
Abstract: A liquid crystal display baseband noise, whose spectrum is much lower than RF bands, is modulated with the carrier signal of cellular communication and interferes with an Rx receiver resulting in a desensitization problem The modulation phenomenon is modeled with impedance parameters and a modulation coefficient The coupled noise on the embedded cellular antenna is experimentally validated in both small- and large-frequency offset cases In addition, to estimate the modulated noise coupling to the antenna earlier in the development process, a numerical simulation method considering the impedance of display drive IC is proposed successfully validated
TL;DR: Novel de-embedding launch geometries and a simplified analytical procedure are proposed to extract the exact electromagnetic behavior of a through silicon via (TSV) pair from measured data.
Abstract: Novel de-embedding launch geometries and a simplified analytical procedure are proposed to extract the exact electromagnetic behavior of a through silicon via (TSV) pair from measured data. First, the most recent de-embedding method is reviewed and it is deeply investigated using both 3-D simulation and vector network analyzer measurements to accurately evaluate its residual error. Then, some potential sources of error are hypothesized and overcome by the proposed launch geometries based on a de-embedding plane that is able to ensure a TEM (or quasi-TEM) mode propagation. The novel launches are studied through 3-D simulations; the previous de-embedding procedure is updated to consider the fringing effect of the open-end launch, and it is simplified reducing the launch standards from three to two. The proposed launch geometries and algorithm are shown to be more accurate in the TSV pair de-embedding with respect to the method currently employed.
01 Aug 2017
TL;DR: In this article, a method that utilizes a set of measurements and numerical models to estimate worst-case skew for the aforementioned effect is described, where cross-sections are analyzed with Scanning Electron Microscope (SEM) for precise measurements.
Abstract: Skew is unintentionally introduced within a differential pair, through misalignment of conductors and glass fiber bundles in Printed Circuit Board (PCB) dielectric layers. Manufacturers do not control interposition of specific glass bundles to supplied board design (artwork). Therefore, an unknown and random factor is added to each produced PCB. Current paper describes a method that utilizes a set of measurements and numerical models to estimate worst-case skew for the aforementioned effect. First, test vehicles are built, and then cross-sections are analyzed with Scanning Electron Microscope (SEM) for precise measurements. Numerical models are constructed to correlate with real DUT; after correlation is achieved, relative location of conductors to glass bundles is swept to obtain best and worst case skew.
01 Aug 2017
TL;DR: In this paper, a procedure for estimating the location of open or short defects in a Through Silicon Via daisy-chain structure is proposed, at low frequency, through the measured and/or computed Z11 parameter of a three dimensional model in which the short and open defects are intentionally created in specific points.
Abstract: This paper proposes a procedure for estimating the location of open or short defects in a Through Silicon Via daisy-chain structure. The equivalent inductance and capacitance are extracted, at low frequency, through the measured and/or computed Z11 parameter of a three dimensional model in which the short and open defects are intentionally created in specific points.