ABSTRACTS:
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ACCELERATE MULTI-FABRIC PDN DESIGN AND ANALYSIS
This demonstration teaches a methodology using the Cadence Sigrity PowerTree technology to improve productivity and maximize the efficiency of multi-fabric PDN system design and analysis. This tutorial caters to a broad audience from design engineers, layout designers, and power integrity engineers who want to analyze their multi-fabric PDN system. PowerTree is a vital piece of this flow.
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ANOTHER CONDUCTED EMISSIONS DEMO?
Sponsored by TC-7
This presentation will focus on the fundamentals of what causes emissions problems and how to reduce the levels without focusing on any particular standard. We have a low voltage (<60V) test setup to demonstrate filter design for conducted emissions. In this demo we will power up a specially designed power supply (flyback, buck or boost) and test if the board passes conducted emissions. Then we will discuss how to reduce the emissions by designing a filter. What core material to choose? What inductance? Do you need to worry about safety? What about EFT? Ultimately, we will test everything live to prove the filter design works. We will also discuss how common mode currents can cause problems in the radiated emissions spectrum.
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A NOVEL CYLINDRICAL MODE FILTERED SVSWR METHOD FOR ABOVE 18 GHz EMC TEST SITE EVALUATION
It has been shown that the conventional SVSWR measurement method does not extrapolate well to above 18 GHz. A novel SVSWR method based Cylindrical Mode Filtering is being actively considered in both ANSI C63.25 and CISPR 16. In the new method, the transmit antenna (typically a low gain omni-directional antenna) is placed at the edge of the turntable, and a single cut vector pattern measurement is acquired. The vector S21 as a function of turntable angle at each frequency is transformed to the cylindrical mode spectrum, where an appropriate filter can be applied to mathematically remove the chamber effects. The SVSWR is derived by comparing the original pattern in the chamber to the “clean” filtered pattern. Compared to the traditional SVSWR method, the mode filtered SVSWR method is easier to perform, faster, more repeatable, and provides a more comprehensive evaluation of the quiet zone. In this demonstration, we will show the measurement process in real time and explain the post processing procedures. Several recent advances will be discussed, including the statistical based robust calculation of SVSWR, and a new post processing algorithm which greatly relaxes turntable positioning accuracy requirements.
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A RECENTLY DEVELOPED GATING LIBRARY FOR ENHANCED POST-PROCESSING
Sponsored by TC-6
Gating is a well-known technique to remove or isolate responses in a multiple reflective environment. The gating technique is widely used in vector network analyzers (VNAs). In this demonstration, we will first discuss the implementation of the gating function in commercial VNAs, and then highlight the benefit of applying the post-processing function as a software library. A software library has been developed recently to provide users with the convenience, flexibility and control of the process rather than relying on the limitations of VNAs. Users have the flexibility to process the measurement data anytime anywhere. The library can seamlessly integrate with conventional programming languages such as Matlab, Python and C. Apart from its convenience, the library has numerous applications that cannot be readily obtained using the gating function of VNAs. In the demonstration, the vector response will be measured between two antennas at a given distance. The antenna response will be gated in real time. We will utilize the library using a Matlab script and select the gate, e.g. gate center, gate width, gate type, gate shape, and edge treatment. Next, three cases will be demonstrated to show the benefits of the gating library compared to the time gating function within a VNA. For each case, we will use the library to process data in real time. The three cases include: 1. Time domain gating for antenna planar near field measurement; 2. EMC chamber VSWR debugging; and 3. Spectrum mode filtering for an antenna extrapolation range.
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CABLING AND SHIELD TERMINATIONS
Cabling and shielding are among of the most important aspects of any system for establishing electromagnetic compatibility. Despite this, they are frequently misunderstood and/or overlooked. This demonstration examines cabling and shielding techniques in order to provide a practical understanding of how shielding works and what types of terminations work best for different applications.
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COMMON MODE CURRENTS, LOOP IMPEDANCE, AND THE USE OF FERRITES
Understanding Common Mode Current and how it is generated is important for the control of radiated emissions. This demonstration will discuss and show how the loop impedance affects the return path of the current over frequency. There will be an explanation of the physics behind the signal path taken for the return signal. Finally, a discussion on how the use of ferrites can influence the return path of the signal, and limitations on the use of ferrites at high frequency.
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CROSSTALK REDUCTION BETWEEN PCB TRACES BY VARYING THE PCB BOARD GEOMETRY AND UTILIZING A GUARD TRACE
This demonstration addresses the crosstalk reduction between PCB traces by varying the PCB board geometry (distance between the traces and distance from the traces to the ground plane), as well as utilizing a guard trace as a shield. The shield is either floating, grounded at one end (to reduce capacitive coupling), or grounded at both ends (to reduce both the capacitive and inductive coupling).
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DEMONSTRATING EMI GENERATION FROM BATTERY PACKS AND A FIELD CANCELLATION METHOD FOR MITIGATION
While EMI has been extensively studied for decades, it appears that EMI generation from battery packs is not well known and has not been well investigated. In this demonstration, we will show that a lithium-ion battery pack used for powering a wearable electronic device commonly used in US underground coal mines (i.e., a continuous personal dust monitoring (CPDM)) can generate strong EM emissions that interfere with other mining safety equipment, such as proximity detection systems. We will also show that the EM emissions generated by the battery pack can be effectively mitigated by a novel EMI mitigation method that is based on a field cancelation technique.
Background: The CPDM is a mandatary device for underground coal miners, according to the Mine Safety and Health Administration (MSHA) regulation (30 CFR § 75.1732). It protects the health of the miners by monitoring a miner’s dust exposure. Unfortunately, not long after the CPDM was placed in the field, it was discovered that the electromagnetic energy emitted by a CPDM interfered with another critical device, called the proximity detection system (PDS), which monitors the distance between miners and mining equipment and protects miners from being accidentally pinned or crushed by mining equipment.
After the incidents of EM interference, an investigation followed, and it was concluded that the battery was the major culprit of the EM emission of the CPDM. Several electromagnetic interference (EMI) mitigation methods were then proposed by vendors and by researchers at the National Institute for Occupational Safety and Health (NIOSH). These include, but are not limited to, a copper-mesh pouch made by Strata (the PDS vendor), shielding on the battery pack, administrative control on the miners (maintaining six-inch distance between CPDM and PDS device), and others. Each method has its pros and cons; yet none of them has addressed the issue satisfactorily.
In this demonstration, we will present a new method that we discovered during our research. It can effectively address the problem. The new method is based on the concept of magnetic field cancellation. The idea is to utilize the coherent nature of the currents in battery cells and rearrange the cells in such a way that the magnetic fields produced from the cells are cancelling each other.
First, we will show that the difference of the EM emission between the stock battery and the newly designed battery when each of them is powering the circuit board of a CPDM. To isolate the EM emission of the battery from that of the circuit board, a half-meter-long shielded cable will connect the battery to the circuit board. The circuit board is then housed in a shielded enclosure. The new battery has the same serial and parallel configuration of battery cells as the stock battery, which is 2S/5P. The new battery also has the same shape and size so that it can replace the stock battery in existing CPDM devices. The experiment uses an RE101 passive loop antenna and a spectrum analyzer to measure EM emission. The result will show that the EM emission is reduced on every side of the battery.
Then, we will install the battery pack into the CPDM device and measure EM emission from the CPDM device. It will once again reveal that the CPDM with a new battery, compared to the one with a stock battery, has less EM emission on most of the sides, especially in the area close to the battery. The new battery design has been reviewed by the CPDM manufacturer and is being considered for implementation in their future product.
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DEVICES POWERED FROM ENERGY HARVESTING
Sponsored by SC-1
Problem Statement: Our environment is in change and everything will be “electronified”. Our glasses, our hand gloves, shirts, shoes etc. can be connected already today with our smartphones and can send commands to the machinery surrounding us. We want this comfort and we are looking forward to having Smart Homes. The point is that we did build our house and we did not implement LAN CATx cables to our coffee machine or refrigerator and even all our lights are not using PoE. If you build a new house and want to implement this data cables additionally, you will think about it twice because it will raise the price. The alternative solution is to use wireless communication. But we do not want to live in electrosmog, where all this devices are continuously emitting and those devices should transmit only on request. Furthermore the efficiency should be not negatively influenced and we should all look for Energy Star certified devices.
State of Technology: We could use WiFi in all those devices and that could be the simplest and easiest way. The cost of implementation would be quite high and additional technical knowhow for maintenance from the user´s side is requested. To solve this situation the design engineer will decide to use a proprietary system SRD where the ISM band is used to be cost effective.
Solution: Chip manufacturers [1], have introduced to market a new generation of processors which have already the RF module in the chip himself. Built is an ARM Cortex M4 CPU platform which can be used until 48MHz clock and the RF stage form 145MHZ to 1050MHz for transmission. This solution is amazing, low current hungry and can operate with 40nA@3V in Sleep Mode. In case of transmission, the current is 18mA @ +10dBm. At this point, we can start to harvest the energy surrounding this application and power our device. For such solution, a power converter manufacturer [2] developed a new chip, which is able to harvest multiple sources. It can be used a piezo or inductive harvester if we have movements, or in case of temperature differences we can harvest from a TEG, or we can use the solar input and harvest the light from the ambient. All that, with just one single chip. If we did harvest enough energy to power but the harvested energy is still present, we can store it with the same chip into a capacity bank, then into a Supercap (balancer in chip) or even charge a Li-Ion battery. Additional input, for a backup battery is also available in the same chip.
With only 2 IC’s we can realize many nice projects and most ingenious self- sustaining devices with no maintenance. In our presentation we will show how easy is to start designing energy harvesting powered products and how to evaluate different harvesters. After the theoretical part, there will be a short demonstration about energy harvesting, using standard components available from different IC manufacturer.
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DIRECT RADAR PULSE MEASUREMENT AND OTHER APPLICATIONS OF FAST E-FIELD PROBES
Sponsored by TC-2
Radar pulse measurements are usually performed in the signal chain between generator and transmitting antenna.
LUMILOOP will demonstrate direct measurement of radar pulses in the electric field, exactly at the location of a DUT. A LSProbe high-speed E-Field Probe and a LSPM RF power meter are combined to evaluate the typical 3 µs pulses used in automotive component testing.
The demo will also feature high-speed E-Field mapping. A LSProbe E-field probe, a LSPM Powermeter and a RF signal generator are orchestrated by our PixEdust® software. PixEdust utilizes the frequency sweep capability of all these devices to iterate quickly through a frequency list. This method reduces measurement time per spatial point down to single-digit seconds. A complete IEC 61000-4-3 17 point field uniformity evaluation can easily be performed in under one hour. We will demonstrate this live in a small-scale setup.
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EFFICIENT ANALYSIS OF ELECTRICALLY LARGE EMC PROBLEMS USING PARAMETRIZED SPHERICAL WAVE BASED MACRO MODELS
Sponsored by TC-9
Traditional full-wave electromagnetic (EM) simulation tools offer a high degree of flexibility to efficiently model EM emission, immunity, and radiated coupling for a wide range of 3D geometries in complex electromagnetic environments. However, for practical EMC problems, these full-wave solvers can be computationally intensive, particularly when analyzing complex structures in an electrically large environment, where the broadband and unintentional radiation characteristics of DUTs interactions need to be considered. To address this issue, we proposed an efficient framework that utilizes the Spherical Wave Expansion (SWE) theory. This framework decomposes the computational domain into pre-computed parameterized macro models and subsequently combines the individual results using appropriate system level simulation engines. The proposed theory offers a suitable SWE higher order mode truncation scheme that allows for the coupling of spherical modes between DUTs with high precision in both the nearfield and farfield regions, without the requirement of running a combined model. Decoupling the macro model simulations leads to significant reductions in memory/disk requirements and overall simulations times by an order of magnitude or more in typical situations. A subset of the parametric/what-if EMC investigations especially those involving changes in orientation and separation between DUTs are extremely faster comparing to traditional methods. The performance and accuracy of the proposed method is evaulated using several examples including complex PCBs and standard antenna types commonly used in anechoic chambers.
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IMPACT OF DECOUPLING CAPACITORS AND EMBEDDED CAPACITANCE ON IMPEDANCE OF POWER AND GROUND PLANES
In Part I we investigate two four-layer PCBs with the power- and ground-plane pairs spaced 3 mils and 30 mils apart, respectively. The boards are populated with decoupling capacitors of the same value (1nF), placed at three different distances from the measurement point.
In Part II we use the 30-mil boards and populate them with multiple capacitors of the same value, as well as with the capacitors of different values, decades apart. The location of the capacitors for all cases in this study is 1 inch away from the measurement point.
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IMPACT OF DECOUPLING CAPACITORS AND TRACE LENGTH ON SIGNAL INTEGRITY IN A CMOS INVERTER CIRCUIT
This demonstration shows the impact of the decoupling capacitors on the signal integrity at the VCC and GND pins in a CMOS inverter circuit. The length of the traces from the power source to the load is varied to change the loop inductance of the circuit. Waveforms at the VCC and GND pins, with respect to the source ground, with and without the decoupling capacitors are measured. The impact of the trace length and the capacitors on the power rail collapse and ground bounce is explained.
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MULTIPLYING COMPETENCY: REMOTE & AUTONOMOUS CHAMBER VALIDATION
The proposed activity is a real-time demonstration of remote chamber validation capabilities for at least three labs of diverse geography, industry served, and measurement needs in the United States and Canada. An engineer (one of the presenters) will be shown remotely controlling testing at all sites simultaneously from the Symposium during the presentation. The remote test site participants represent a large segment of the EMC and SIPI community and provide relevance to different market segments of manufacturers and service providers in the Symposium audience. The development and implementation of remote chamber validation with autonomous measurements presents a significant efficiency improvement to the industry, while requiring lower on-site competency. Attendees will learn the advantages of remote testing, watch a live demonstration of its practical application, and have an opportunity to interact with the presenters for a question period.
Several commercial and private lab owners have expressed commitment to the demonstration, including automotive labs wishing to demonstrate the CISPR 25 long-wire testing and OEM labs with Near Field Scanning facilities. The presenters will select a group that contains:
• A commercial test lab with 3m SAC in the Southwest United States
• A private Canadian R&D reverberation chamber
• An EMC manufacturer with an internal SAC
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PCB TRANSMISSION LINE ELECTROMAGNETIC EFFECTS
This hands-on demonstration will show basic electromagnetic principles in Transmission Lines [TL] on a simple two sided printed circuit board . The intended audience is DIY [do it yourself] engineers/students. Low cost USB RF instrumentation will explore applicable EM topics. PCB design available on GIT-HUB.
EM Mechanisms to explore:
The importance of impedance control on transmissions lines through trace widths and reference plane control either on the same side of PCB or on other layers
• Impacts of meandering Transmission Lines on insertion loss
• Impacts of ground plane slots in/near transmission lines
• Impacts of improper ground reference control on TL and or shielding effects
• Impacts of interfaces on transmission lines (filters, open lines, shorts, termination impedance
The above topics will be explored to at least 500 MHz, within the capability of readily available USB instruments such as nanoVNA and TinySA [ reference web links] The trends seen at frequencies less than 500 MHz will scale as frequency increases, and issues seen at these lower radio frequencies will worsen as the frequency increases.
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SELECTION OF MAGNETIC SHIELDING FOR OPTIMIZING NFC/RFID SYSTEMS
Sponsored by TC-4
Incorporating Near Field Communication (NFC) into embedded portable devices can lead to magnetic field interference due to the presence of conductive surfaces like batteries, ground planes, and metallic enclosures. To address this issue Flexible Sintered Ferrite Sheets (FSFS), represent an interesting shielding solution to prevent EMI problems related to NFC thanks to their ability to control the magnetic flux.
The characterization of FSFS effectiveness is analysed as a function of the sheet thickness in this contribution. This is performed with the aim of determining which is the optimum thickness value to retune an NFC antenna to its original operation frequency value (13.56MHz) when it is affected by a near conductive surface.
A finite element method (FEM) simulation model is designed and corroborated with the experimental results to evaluate the performance of different FSFS thicknesses in terms of resonant frequency shift, magnetic field strength and communication distance.
This contribution studies the influences of different setups, on a demotool, of conductive surfaces close to the transmitting antenna and how they change its behaviour.
The results obtained show that the magnetic field strength is significantly attenuated, and the communication distance is highly shorted. Therefore, besides selecting a material that provides high reflection and low losses at 13.56 MHz, it must be considered the thickness to ensure the greatest communication effectiveness. Consequently, the use of a wrong FSFS thickness could lead to shifting the resonance frequency to lower values than expected, detuning the communication.
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SIGNAL COMPARISION IN TIME DOMAIN AND FREQUENCY DOMAIN
In this experiment, the presenters will compare the signal waveform in the time domain and frequency domain. The measurements will show the results from the Oscilloscope and Spectrum Analyzer. From the Oscilloscope, the presenter will use the time domain and FFT results and from the Spectrum analyzer, and show the frequency domain and zero span results. The Zero span feature of the spectrum analyzer enables the time domain measurements for us. Lastly, the presenter will compare different waveforms and the results from both Oscilloscope and Spectrum analyzer and compare the results, and in conclusion, show the advantages and disadvantages of each method and measurement facility.
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SIMULATION OF CONDUCTED AND RADIATED EMISSIONS FROM POWER ELECTRONICS AND CONNECTED CABLES
Sponsored by TC-9
Modeling EMI/EMC of power electronics is necessary but challenging, the repetitive on/off transitions of the switches is an inherent source of high frequency noise to couple through heatsink or radiate from cables. It is the derivates in the voltage and currents from these transitions that cause issues for typical SPICE based simulation tools, these solve engines are simply not optimized to deal with the switching introduced from modern power electronics. This leads to a typical workflow that includes no simulation, with all discovery occurring “in the chamber” with a physical prototype. Additionally, the presence of a distributed cable model with very small inductance and capacitance values can lead to very challenging time constants for the solver to compute. What is required is a purpose-built power electronics simulation tool with a simplified device model that can accurately model turn on/off dv/dt and di/dt without being overly complex to solve. With a reliable solve of the device transition we are able to introduce the common mode and differential mode parasitic paths required to understand conducted EMI. Additionally, if the power converter includes cable connections, we can introduce a per unit cable model based on the Multi Transmission Line, MTL, method from a 3D solver environment. The MTL method allows us to include cable type, shielding, and routing configuration into the model. With the cable now included in the simulation of the power converter we now have a more complete understanding of the conducted EMI; furthermore, we can also link back to a high frequency electromagnetic (EM) solver to simulate the radiated emissions from the cable. This workflow of studying radiated emissions from a cable connected to power electronics is novel and significant development to include simulation into existing workflows that are based solely on hardware testing. During this software demo we will go over the details of simulation of power electronics for conducted EMI as well as the use of 3D EM simulation tool for radiated emissions from cables connected to power electronics.
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THREE TUTORIALS & SOFTWARE DEMONSTRATIONS TO INTRODUCE STOCHASTIC SIMULATION FOR INTERACTIVE EMC DESIGN
Designing cables, connectors and enclosures for EMC compliance at system-level and at high frequencies is difficult, due to coupled conduction and radiation paths, shield/joint/seam leakage, connector and cable penetration uncertainties, excitation field complexity, etc. For most EMC engineers, numerically-meshed, full wave models are too large, expensive and slow to be an interactive design tool – particularly at high frequencies 1GHz and above. New, statistically-reduced order models by comparison, are a more natural solution for his class of problem, applicable up to 10 Ghz and beyond.
STOCHASTICA software from RobustPhysics will be used to demonstrate how the new stochastic simulation facilitates fast, interactive EMC environment predictions – both currents on cables and coupled electric fields in reverberant enclosures - in minutes rather than days.
Combined Tutorial and Software demonstrations for three (3) different EMC design applications are proposed, to be presented in one hour sessions in Exhibit Hall on Days 2, 3 and 4 of the Symposium.
Day 2) Shielding Effectiveness Design to 10GHz and beyond, using Fast Stochastic Simulation
Day 3) Conducted and Radiated Crosstalk between Shielded Cables, using Fast Stochastic Simulation
Day 4) Predicting Integrated System EMC Levels for Test Level Tailoring , using Fast Stochastic Simulation
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VIRC: SHAKE IT TILL YOU MAKE IT!
This E&D focuses on presenting a portable vibrating intrinsic reverberation chamber (VIRC) setup to explain the basic concepts of reverberation chambers (RCs). As opposed to conventional, rigid-wall RCs, a VIRC is made from a flexible conductive material and therefore can be easily transported to perform both radiated emission and immunity tests on site, yet their underlying functionalities are similar. By performing a series of experiments, this E&D intends to educate the viewers for whom the statistical aspects of the techniques used in RCs are still a mystery, or would like to expand their understanding of this measurement technique.
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