Presentation Abstract

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1 Presentation Abstract P1. IC to Victim Antenna Near-field Coupling Estimation - L. Li (S&T) In mixed radio-frequency (RF) and digital designs, noise from high-speed digital circuits can interfere with RF receivers, resulting in RF interference issues such as receiver desensitization. A common noise-coupling path is between the working IC and a receiving antenna. Reciprocity theorem is proposed here to calculate the coupled power. The problem is divided into two steps. The first step is to characterize the working IC noise, the second step is to characterize the RF antenna. Then the reciprocity theorem is applied to calculate the coupling. Both are proposed to be implemented by near-field scanning measurement. The method is validated through a test board with a clock buffer and a patch antenna. It fits well with engineering practice, and is particularly suitable for pre-layout wireless system design and planning. P2. Conducted-Emission Modeling for a Switched-Mode Power Supply - Y. Wang (S&T) Total voltage sources and Thevenin s equivalent circuits are derived by measurements to characterize the conducted emissions from a switched-mode power supply (SMPS). The constructed noise source model for the test IC is employed in system-level simulations and the calculated coupling to an antenna is validated by measurements. The agreement between simulated and measured results demonstrates the effectiveness of the constructed model for characterizing the conducted emissions from an SMPS. P3. Effect of Number of Decoupling Capacitors on Equivalent Inductance of PCB PDN -B. Zhao (S&T) Printed circuit board (PCB) power distribution network (PDN) design forms a critical part of system design for the high speed digital systems. A part of the design problem is to determine if the number of decoupling capacitors placed at each power net is sufficient. An approach is proposed to find the number of decoupling capacitors required on the PCB PDN by studying the convergence of the equivalent inductance as seen by the integrated circuit (IC) looking into the PCB PDN. This equivalent inductance is calculated with a physicsbased circuit model extracted from the cavity model approach inside the frequency range of interest. P4. Reflection and Insertion Loss Jitter Based on Transfer Function Decomposition - Q. Huang (S&T) A new transfer function separation method is proposed to separate the insertion loss jitter and reflection loss jitter. Several simple and ideal channels are used as examples to demonstrate this idea. Measurements are also done to show the application of this method. P5. Transmission line de-embedding Method with S-parameter Renormalization -B. Chen (S&T) In this work, a de-embedding method for transmission line DUTs is presented. With a dramatically reduced number of measurements, the proposed methodology is extremely convenient for calibration pattern design, as well as frequency and time domain measurements. By introducing the time-domain method of characteristic impedance acquisition, renormalization is performed to get actual S-parameters in any impedance system. An error bandwidth is predicted before the de-embedding procedure, and a first order error approximation is analyzed to quantify major mistakes in de-embedded results.

2 P6. Modeling of Cable Discharge Event (CDE) into Ethernet magnetics using a CDE Test and Measurement System -G. Maghlakelidze (S&T) If a charged cable connects to a device, an electrostatic discharge (Cable Discharge Event CDE) is observed. Ethernet communication interfaces are often affected by CDE. The discharge process is quite complex due to the internal structure of the connector, pin discharge sequencing, and the connection to other systems. In the event of CDE, a pulse couples to the PHY side through the Ethernet magnetics - typically a transformer and a CM choke. A CDE test system is used for a variety of repeatable tests. This poster describes a simulation model for the test system and various test setups for testing of Ethernet magnetics. P7. ESD Prediction Based on Power Domain Network Measurement and Modeling -S. Yang (S&T) A nonlinear power distribution network model for characterizing the immunity of integrated circuits (ICs) to electrical fast transients (EFTs) is proposed and validated. This model includes electrostatic discharge (ESD) protection diodes and passive impedance between power domains. Model parameters are measured using VNA and TLP generator. The model is able to successfully predict pin currents and voltages during EFTs on the power pin when the IC is operating or turned off and when the ESD protection is activated or not. P8. On-die Sensors for Transient Events -M. Suchak (S&T) Determining the cause of an ESD failure or determining which components are impacted by a system-level ESD event is challenging. Sensors have been developed which can be implemented on-die, in a microcontroller or other IC, to determine which I/O pins are affected by an ESD event and the level of the event at those pins. The sensors do not require significant die area and have low static power consumption. Sensor designs have been verified in simulations which comprehend the entire IC I/O ring and package and which account for manufacturing variations in sensor components. Initial results demonstrate that the sensors are capable of accurately sensing a transient electromagnetic event. A test IC is currently being developed to validate the sensors in hardware. P9. Impact of Feedback Loop Noise in On-chip Voltage Regulator Module (VRM) -S. Kim (S&T) On-chip voltage regulator modules (VRMs) contain a feedback network to reduce the power/ground noise throughout the power distribution network (PDN). The effects of loop noise in the feedback circuit are examined in this project. P10. 1 Gbps on Unshielded Wiring Harnesses in an Automotive Environment -T. Hubing (Clemson) At very high data rates, radiated emissions and immunity problems are generally the result of a failure to maintain a constant level of electrical imbalance in the common-mode signal path. This allows commonmode currents to couple to an antenna mode. Existing solutions to this problem involve the use of isolation transformers and common-mode chokes in or near the board/cable interface. These magnetic devices are designed to attenuate the common-mode and therefore reduce the antenna-mode voltages that ultimately drive the structure. An alternative solution is to eliminate the changes in electrical balance in the signal path that convert common-mode currents to antenna-mode voltages. This presentation describes a design

3 approach being evaluated at Clemson University with the goal of transmitting 1 Gbps signals on unshielded wiring harnesses in an automotive environment. P11. Prediction of Radiated Emissions from Cables with Multiple Connections to a Metal Plane -G. Li (S&T) The radiated emissions from a partially shielded cable mounted 5 cm above a metal plane are found to be dominated by the emissions from the 5 cm vertical conductor segments, which connect the cable shield and the signal wires to the metal plane at various locations. Assuming a noise source voltage and impedance driving the structure, circuit theory was used to calculate the currents through the various vertical dipolelike antennas. Then, the total radiated electric field from the dipole array was calculated analytically. Finally, the antenna factor was applied to calculate the radiated emissions, which were compared to full wave simulated results. This same procedure can be used to determine if a system might meet a given radiated emission specification before actual testing is done. If the radiation is predicted to be excessive, then design changes, such as additional filtering, can be modeled analytically before the cabling is built to determine if the changes will allow the system to meet the radiated emissions specification before testing begins. P12. Terminal Model Investigation for Characterizing Conducted EMI in Boost Converter System -G. Shen (S&T) A terminal model is a common method to create equivalent models of boost converters in order to predict conducted emissions. In this paper, the voltages across and currents flowing into the input side of a DC-DC booster converter were used in the equivalent source modeling. The converter can be considered as a Thevenin voltage source, Vt source was determined; the actual induced voltage at the LISN side was compared to that predicted by the model to estimate its accuracy. The methodology was tested both in simulation and measurement. The results indicate that the agreement with the direct model is quite good up to 100 MHz when the load is within the characterization range; the difference is around 5 db when the test load is out of characterization range. P13. Phase Measurement using Spectrum Analyzer -S. Marathe (S&T) Phase resolving near field scanning can be directly performed using an oscilloscope and a VNA. Spectrum analyzers are relatively cheap and widely available. The goal of this project is to measure magnitude and phase using a spectrum analyzer. Different phase resolving measurement methods using a spectrum analyzer are explained and compared with respect to robustness, broadband or single frequency measurement ability and their ability to handle time varying signals. P14. Studying the Effect of Drilling Uncertainty on Signal Propagation through Via -Y. Wang (S&T) The effect of four major manufacturing uncertainties on the differential input impedance of via is studied by different methods. Firstly, design of experiment (DoE) method is applied to roughly determine the most influential factor on the differential input impedance of via. Then the polynomial chaos (PC) method is implemented to quantify the uncertainties. The effectiveness of the PC method is validated by the Monte Carlo (MC) method. Finally, the advantages and disadvantages for all the three methods are compared and practical suggestions on the usage of these methods are given. P15. Absorbing Material Placement in Heatsink Radiation Reduction - Q. Liu (S&T) Heat sinks of digital integrated circuits (ICs) are major sources of electromagnetic interference (EMI). Several strategies can be used to mitigate excessive heat sink EMI. One of such techniques relies on placing

4 absorbing material on or nearby the radiating heat sink. The actual placement and amount of the applied absorber plays a significant role in determining the efficacy of the EMI reduction. This study investigated several possible absorber configurations and compares the efficiency of these solutions. In addition to EMI reduction, the influence of the absorbers on signal integrity (SI) performance of nearby traces is also discussed. P16. EMI Analysis and Modeling of a Flat Panel Display -S. Shinde (S&T) EMI analysis and modeling was performed of the radiated emissions from a TV that consists of multiple electrically large components. Multiple noise sources were modeled and used as an excitation signal in a full wave simulation model. P17. Physics-based SPICE Model Reduction from a Large Scale PEEC Model -N. Bondarenko (S&T) In power systems, interconnect parasitic have an important effect on Electromagnetic Interference (EMI). Simple physics-based lumped-circuit models are useful for fast analysis and better understanding of system performance. In this work, a methodology is developed for obtaining a simplified SPICE circuit from a large scale Partial Element Equivalent Circuit (PEEC) model, where parasitic circuit elements can be clearly correlated to parts of system geometry. In recent months, the proposed technique has been extended to develop analytic methods for breaking current loops in the system to allow mathematical circuit reduction and to automatically create capacitive groups. The proposed method has also been applied to more complex geometries, consistent with a power inverter DC link.

5 List and Abstract of Posters p1. Estimation of TRP in the Sparse ESM - O. Kashurkin (S&T) Sparse Emission Source Microscopy (ESM) technique provides a powerful tool for locating the sources of radiation in GHz range. This technique reduces scanning time by eliminating the need to perform scanning with regular sampling step, but at the expense of reduced dynamic range and undefined absolute values of reconstructed fields and, hence, the Total Radiated Power (TRP). In this project a method for TRP estimation in sparse ESM is proposed. This method uses extrapolation of the calculated TRP dependency over the number of acquired field samples and allows measuring the TRP with accuracy of several db for quick sparse scans with duration below 10 minutes. p2. Differential Mode Scattering Parameter Measurement by Using Single-ended Probe -B. Chen (S&T) A new method for differential probing measurement is developed by taking advantage of modal concept. With a pair of single-ended micro probes, differential S-parameters of a DUT could be achieved by a process of smart fixture de-embedding (SFD) techniques, without performing a calibration procedure on an impedance substrate or traditional TRL calibration. p3. Investigation of S21 Extraction Methodologies by Using a Pattern Generator and a Sampling Oscilloscope -X. Guo(S&T) S-parameter measurements of a digital link path are measured with VNAs or high-end TDRs. For multi-port in-situ measurements, these become inconvenient and time consuming. However, it can be handled more conveniently in the time domain (TD) by using a pattern generator and a multi-channel sampling oscilloscope, which are used for eye-diagram measurements. This paper outlines and compares three methods to extract S21 magnitude from the time domain measurements using a pattern generator and a sampling oscilloscope for any channel. The setup differs in terms of the input waveform and the processing. The comparison provides insight into the advantages and limitations of each method. p4. Designing a 40GHz Automotive Channel Emulator Based on MEMS Switch - J. Sun(S&T) This ongoing research focuses on building a channel emulator that can be integrated into automotive test systems based on the MEMS Switch. Multiple coplanar waveguide channels are designed with different lengths. The trace between transmitter and receiver can be switched between these channels to explore the transmission performance under different channel S-parameters and frequencies. A novel component--the MEMS Switch--is chosen to control channel switching due to its low insertion loss, high isolation and programmable configuration. As a result, different channels can be emulated automatically and accurately without additional human interference. p5. Shielding Methods for Broadband Analog IC Packages -B. Conley(S&T) Coupling between closely-spaced, wideband RF ICs can cause degradation in device performance. Various methods of reducing this inter-package coupling have been tested, with a strong focus on maintaining manufacturability and minimizing the increase of intra-package coupling. This was accomplished through both full-wave simulation and physical measurement of inter-package coupling and total radiated power.

6 p6. Effectiveness Analysis of De-embedding Method for Typical TSV Pairs in a Silicon Interposer -Q. Wang(S&T) In this paper, a de-embedding method to extract the performance of a Through-Silicon-Via (TSV) pair is proposed, using a set of specially designed test patterns to remove the pads and connection trace. In realworld use, wafer probe measurements require physical access to the test structures, and any errors in the probe calibration will affect the test pattern measurements. As such, a micro-probe model is built in with the test. Short-Open-Load (SOL) calibration method is used with the simulation results to calibrate to the tips of the micro-probe used in all test patterns. Calibrated responses for the test patterns are used with the previously proposed de-embedding algorithm to characterize the TSV pair. The effectiveness and robustness of the de-embedding method against probe calibration errors are tested with full wave simulation results and analytical calculations. p7. Conductor Surface Roughness Modeling for Stripline Interconnects of variable width -O. Kashurkin(S&T) Copper foil roughness affects the signal integrity performance of transmission lines, especially at high data rates (10Gbps and above). Existing transmission line models cannot predict the effect of roughness with desirable accuracy. This project presents a new model that approximates the effect of transmission line conductor roughness by introducing empirical correction coefficients derived from a set of striplines with trace widths between 3 and 15 mils and foil types with roughness from HVLP to STD. p8. Effect of Number of Decoupling Capacitors on Equivalent Inductance of PCB PDN -B. Zhao(S&T) Printed circuit board (PCB) power distribution network (PDN) design forms a critical part of system design for the high speed digital systems. A part of the design problem is to determine if the number of decoupling capacitors placed at each power net is sufficient. An approach is proposed to find the number of decoupling capacitors required on the PCB PDN by studying the convergence of the equivalent inductance as seen by the integrated circuit (IC) looking into the PCB PDN. This equivalent inductance is calculated with a physicsbased circuit model extracted from the cavity model approach inside the frequency range of interest. p9. Analytical PDN Voltage Ripple Calculation Using Simplified Equivalent Circuit Model for PCB PDN -B. Zhao (S&T) Printed circuit board (PCB) power distribution network (PDN) design performance depends on the peak voltage ripple caused by the integrated circuit (IC) switching currents. The input impedance seen by the IC looking into the PCB PDN can be calculated using a physics-based circuit model extracted from the cavity model approach. The input impedance is fitted to a simplified circuit model used to represent the PCB PDN. Using a switching current profile, the frequency domain noise voltage is found and transformed to the time domain ripple waveform which can then be used to evaluate the PDN design performance. p10. Frequency Domain Methods for Causality Enforcement -M. Zvonkin (S&T) Different errors such as frequency-dependent measurement errors or errors due to the numerical simulations and/or discretization may seriously affect the causality property of a physical system. Major non-causality will directly change the time domain simulation results, and minor non-causality may get amplified in frequency domain modeling procedures such as cascading and de-embedding and invalidate the overall channel simulation outcome. Therefore, it becomes essential to develop a methodology of quantitatively assessing non-causality and enforcing the causality when violations are not major. In

7 practice, the channel is characterized in the frequency domain and this data is manipulated in the frequency domain to obtain an overall channel transfer function. Thus, it is preferable to have a frequency domain methodology for enforcing causality. This work presents two approaches for enforcing causality in frequency domain, based on the Kramers-Kronig relations between real and imaginary parts of the transfer function and magnitude and phase of the transfer function, respectively. p11. Transfer Function Interpolation Problems for Long Structure - M. Zvonkin (S&T) System-level simulation for signal integrity usually requires connecting together models of various subparts. Different measurements and/or simulations might be sources of frequency characteristic data corresponding to those subparts. The frequency characteristics might be measured or simulated for different frequency samples. To obtain the whole system it is necessary to cascade the frequency characteristics corresponding to subparts of the model. Frequency characteristics can be cascaded only if they are given at the same frequency samples. Thus, the interpolation of such frequency responses is necessary to reduce the data to a common set of frequency samples. Incorrect interpolation might create problems, especially if the model has a long structure. In the present work, interpolation problems of frequency response data are studied. A practical solution for this problem is suggested and different measured and simulated test cases are investigated. p12. Estimation of ESD-Related Risk in Data Centers -A. Talebzadeh (S&T) The effect of changing environmental relative humidity (RH) and temperature has been analyzed to evaluate the incidence of electrostatic discharge (ESD) related failure at data centers. To this end, various RH and temperature are considered: 45%RH & 27 C, 25%RH & 27 C, 8%RH & 27 C, and 8%RH & 38 C. At each environmental condition, twcfo walking experiments (i.e. well-defined walking pattern and random walking) are conducted for 100 seconds with different kinds of shoes and flooring material. Then, the measured electrostatic voltage is extrapolated to estimate the ESD damage risk. Moreover, Chebyshev s Inequality is used to predict the upper bound for the probability of ESD-related failures. p13. Optical Tracking System Based 2D Imaging System for EMI Source Localization -H. He(S&T) This research presents an optical tracking, 2D imaging system to localize radiating sources on complex systems. Optical tracking is used for localizing the position of the near field measurement probe. Emission source microscopy (ESM) techniques derived from synthetic aperture radar (SAR) are used to localize radiating sources. After localizing the sources, the far-field contribution and the total radiated power from each individual source can be estimated. p14. Measurement-based Modeling and Worst-case Estimation of Crosstalk inside an Aircraft Cable Bundle -G. Li(S&T) Crosstalk within cable bundles can degrade system performance. In aircraft systems that use shielded twisted pairs, the crosstalk occurs primarily in the connector, where individual signal wires are not shielded or twisted. In many cases, the parameters which determine crosstalk within the connector are unknown, in part because the connector is closed and wires cannot be easily accessed. A methodology was developed for measuring coupling parameters and modelling crosstalk within the aircraft cable connector at low frequencies (< 400 MHz). The values of mutual inductance and capacitance were extracted from measurements made with a Vector Network Analyzer (VNA). The characteristics of the individual wires were extracted from VNA-measured TDR response. The accuracy of the model was evaluated through

8 comparison of simulated and measured results. Furthermore, a closed-form solution is developed to estimate the envelope of the differential crosstalk. The calculated results match the measured peak values well. This worst-case crosstalk estimation allows effective evaluation of the impact of crosstalk within different connectors. The developed method can be effective for analyzing complex aircraft cable assemblies and connectors without requiring extensive knowledge of the assembly procedure. p15. Radiated Emission Source Analysis and Prediction for Ethernet System - G. Maghlakelidze (S&T) Ethernet communication systems are based on the principle of differential signaling. Ideally, Differential Mode (DM) signals do not emit unwanted radiation. However, the path along which the signal propagates is not ideal and a portion of DM is converted to Common Mode (CM), causing unwanted Radiated Emission (RE) from a device or its cabling. This poster evaluates the Ethernet link (PHY PCB routing Magnetics PCB routing Connector Cables) for sources of DM-to-CM conversion and Radiated Emissions. p16. Multiple Parallel FIR Channel Emulator Hardware Platform Build-up and Emulation - Q. Wang (S&T) System level design is introduced for hardware system of MFC (Multi-FIR Channel) featuring two Hittite FIR chips. The Hittite FIR chip (HMC6545LP5) is a signal conditioner used as a channel emulator to reproduce different target channel properties. However, this FIR chip only contains 9 taps and 18ps delay between taps. Therefore, for target systems with wide impulse response, a single FIR channel is not enough to cover the entire impulse duration. MFC then will utilize two parallel FIR channels to provide the equivalent capabilities of an 18 tap FIR channel in frequency range of DC to 26 GHz. RF signal splitting and combining for parallel FIR channels is the most critical challenge in this system build-up. Meanwhile, for such a complex RF signal processing system, details to balance different tradeoffs will also be explained. p17. Design and Implementation of Equalizer Based on AEQ Chip - J. Zhou (S&T) Equalizer circuits are designed to compensate the high frequency loss of electronics in a channel emulator system. Our design can provide different frequency responses. It is based on the commercial device AEQ2234 from Dielectric Laboratories. An additional RL branch was introduced to improve the return loss. The effects of resistor location and resistor package size were simulated and measured. Fig. 1 shows the typical performance. The two different structures are capable of compensating 6dB loss or 10dB loss. p18. Modeling Soft Error of SRAM Circuits Due to the Noise Injection to Power/Ground plane - C. Sui(S&T) While IC-level testing helps to establish the immunity of ICs against electromagnetic interference, testing can never ensure the IC withstands all electromagnetic interference events. Even in the case where a soft error is found, it is not always easy to find a way to fix the error. The goal of this research project is to develop predictive models for the immunity of SRAM circuits to electromagnetic events. The immunity characteristics of the SRAM circuits are being evaluated through simulations. The result of these simulations will be used to develop the predictive model. This model will be relatively simple, so that it may be applied even when one does not have complete information about the circuit and so that it may convey a greater understanding about the cause of and solution to immunity issues. A test IC containing an SRAM cell and a printed circuit board to mount the chip has already been built. The function of the test SRAM circuits has been validated through simulation and measurement.

9 p19. De-embedding Method to Measure the Impedance of an Innovative O Shape Spring Contact - Q. Huang(S&T) A de-embedding method is proposed to measure the high frequency impedance of an innovative O-shape spring contact. Results obtained from the de-embedding method are validated using full-wave simulations and measurement results. p20. A Multiple Scattering Method to Analyze Electromagnetic Radiations from Cable Harness inside a Vehicle - Y. Wang(S&T) At present, the available commercial tools dealing with cable radiation and susceptibility problems usually treat the cable harness as lumped element circuits. This approach neglects the secondary and consequently multiple reflections between cables and the metal sheet nearby, which potentially produces inaccurate prediction of the EM radiation. One alternative way is to use Method of Moment (MoM), which is accurate but computationally expensive. In this project, a multiple scattering method based on a hybrid algorithm combining MoM and the MTL theory is proposed in order to take all the noteworthy reflected fields into account to efficiently make the accuracy comparably to that of a pure MoM. p21. A High Frequency H-field Probe Design up to 20 GHz - Y. Wang(S&T) A high frequency H-field probe design is proposed. Instead of the traditional U-shaped signal trace, an L- shaped signal trace is implemented to minimize its corresponding inductance such that the probe can perform well at higher frequencies. Both simulations and measurements show that the probe can work well up to 20 GHz. An application of the probe is given in this project.