SCIF AND RADIO FREQUENCY SECURED FACILITY DESIGN
This paper is intended address the growing confusion in the industry over Sensitive Compartmented Information Facilities (SCIF) design and performance requirements and to bring some clarity to various documents and performance requirements from a RF shielding perspective to aid in the design and construction of these facilities.
Joel Kellogg, Director of Business Development, ETS-Lindgren
Navigating the Selection of Magnetic Resonance Imaging Shielding Systems
All shielding technologies are not equal and consideration of a host of factors should be given when selecting shielding, including performance requirements (E-Field, H-Field, Plane Wave, etc.), the application, quality of products, long-term performance, materials used, and construction methods. This paper explores shielding systems utilized for magnetic resonance imaging (MRI). (c) 2020 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. By downloading this content, you are agreeing to this usage restriction.
Joel Kellogg, Director of Business Development, Healthcare/IG, ETS-Lindgren
5G Millimeter Wave Devices: The Impact on EMC Compliance Tests
The fact is that a tremendous amount of engineering work on test specifications, instruments and firmware is needed before 5G user devices will fulfill the promises made by the carriers. Electromagnetic Compatibility (EMC) is definitely one of the areas impacted, but one of the technical areas least talked about. The demand is growing quickly and there is a massive market for testing these devices, so now is the time to study the issues and prepare the lab for 5G
Mitigation of Band Edge Effects in Fourier Transform Based Time Domain Gating
Time domain gating is a well-known signal processing technique by first converting frequency domain data to time domain via inverse Fourier Transform. Time domain gating is thereafter applied as a filter to include or exclude certain time periods. One of the side effects of time domain gating is band edge effects where data near band edges is unreliable. Several mitigation techniques have been reported and implemented in commercial vector network analyzers, i.e., pre-gate windowing and post-gate renormalization. Even after applying these mitigation techniques, edge errors can still be significant. In this paper, we summarize these common mitigation methods, and utilize a different approach, referred to as Spectrum Extension Edgeless Gating (SEEG) method. In SEEG, frequency domain data is first extended beyond the edges smoothly, and time domain gating is applied over the extended data. In a wide range of antenna measurement applications, SEEG method is shown to be superior for reducing uncertainties from gating edge effects.
Zhong Chen ;
9 13th European Conference on Antennas and Propagation (EuCAP)
Modeling of Tapered Anechoic Chambers
A hybrid method that combines the finite element method (FEM), the Floquet mode analysis and the shooting and bouncing ray method (SBR) is presented to solve the quiet-zone field in large tapered anechoic chambers. In the method, the field equivalence principle is employed to replace the throat of the tapered chamber by a set of equivalent electric and magnetic currents. The Floquet mode analysis is employed to approximate the rest of the absorber lined walls by virtual surfaces with equivalent reflection coefficients. The total quiet-zone field then becomes the superposition of the field radiated by the equivalent currents, and the field scattered by the virtual reflective surfaces. The scattered field is calculated from the SBR method. The required equivalent currents of the throat and the reflection coefficients of absorber array walls are computed with the use of the FEM, which allows the considerations of the complex structure and near-field interaction. Numerical examples are presented to demonstrate the feasibility of the proposed method.
Zubiao Xiong ;
ACTIVE MAGNETIC FIELD COMPENSATION SYSTEMS A COMPARATIVE STUDY
ACTIVE MAGNETIC FIELD COMPENSATION SYSTEMS A COMPARATIVE STUDY
IEEE STD 1128-1998: IEEE Recommended Practice for RF Absorber Evaluation in the Range of 30 MHz to 5 GHz
What is IEEE STD 1128 Recommended Practice for absorber evaluation Current Structure: Instrumentations: Spectrum analyzers, Network analyzers, vector voltage meter, and EMC antennas Material bulk-parameter evaluation: measuring permittivity and permeability Absorber reflectivity: Arch, TEM horn TD method, waveguide, coaxial reflectometer.
ANSI C63.25.1 Validation Methods for Radiated Emission Test Sites
This article consists only of a collection of slides from the author's conference presentation. radiated emission testing; time domain site VSWR method; CISPR 16 SVSWR method; TD SVSWR method; ANSI; transmission lines and frequency domain analysis.
Zhong Chen
Shielding a High-Sensitivity Digital Detector from Electromagnetic Interference
A study at The Ohio State University Wexner Medical Center describes shielding a high-sensitivity digital mammography system detector from AC magnetic fields of magnitudes great enough to induce imaging artifacts. Successful shielding addressed the EMI and removed the imaging artifacts.
David E. Hintenlang, et al
Journal of Applied Clinical
Medical Physics
Testing the 5G New Radio (Chinese)
This paper touches on various issues the industry must address, and the current work in 3GPP, to develop the basis for 5G and mmWave test techniques before the radio design has even been
completed.
Michael D. Foegelle
Testing the 5G New Radio (English)
This paper touches on various issues the industry must address, and the current work in 3GPP to develop the basis for 5G and mmWave test techniques before the radio design has even been completed.
Michael D. Foegelle
Safety & EMC Magazine
Chambers for the evaluation of vehicle mounted antennas
The increasing demand for sensors and systems that use RF communication in one form or another in modern vehicles is driving the growing degree of complexity and control system density. For many of these systems, it is necessary to perform some level of individual performance evaluation that may involve an over the air component in the performance assessment. Although this may be just one aspect o... View more
Garth D'Abreu | Zubiao Xiong | Zhong Chen
Investigation of deconvolution filters for high-resolution time-domain antenna measurements A numerical study
Time domain gating is a common technique in antenna measurements to remove or evaluate the effects of extraneous reflections. Complex valued frequency domain response is transformed to time domain impulse response via Inverse Fourier Transform, so time gating can be applied. This technique relies on enough time separation between the direct antenna response and the late time reflections so that gating can be applied. Long ringing antennas such as log periodic dipole arrays present difficulties in this application. Deconvolution algorithms, such as Wiener filter and inverse filter, have been shown to be effective for pulse compression to increase time-domain resolutions. This paper examines the effectiveness of the filters, with or without measurement noise. It shows that the inverse filter is near optimal, and should be used in most applications
Zhong Chen ;
Regarding the Creation and Use of Dual Antenna Factors for Use in Normalized Site Attenuation (NSA) Measurements
In order to assist a customer with a lower measurement uncertainty contribution, ETS-Lindgren provides customers with a Dual Antenna Factor (DAF). This paper provides an equation to calculate Geometry Specific Correction Factors (GSCF) based on the DAF. GSCF is defined in ANSI C63.5-2017 [1]. GSCF is required for calculating the theoretical site attenuation values for site validation measurements.
Zhong Chen
Addressing the Global Threat of EMP Events: The Impact on Business and Life as We Know It
Maintaining the resiliency
of all Critical Infrastructure Segments, including the electric grid, sensitive
data centers, and vital communication channels, has become a growing concern globally
as Electromagnetic Pulse (EMP) events continue to threaten society and the
operation of business and life as we know it.
Mike Caruso, Janet O'Neil, Bob Piemonte
Common RF absorbers evaluations in W-band (75-100 GHz)
This article consists of a collection of slides from the author's conference presentation. Conventional commercial polyurethane absorbers when optimized can achieve about 35-40 dB reflectivity in W band. Latex paint can degrade the absorber performance. Black tips do not significantly improve the performance. Best absorbers are convoluted absorbers (egg crate shaped). Second best are the 3 or 5 pyramids. Flat absorbers with optimized loading can achieve ~30 dB reflectivity in the W band. Wave can penetrate into the absorbers 1 deep. EMC hybrid absorbers generally can only achieve 20 dB reflectivity.
Free space antenna factor computation using time domain gating and deconvolution filter for site validation of fully anechoic rooms
An alternative method to compute the free space antenna factor using time domain transformation and deconvolution filter for pulse compression is proposed. The deconvolution filter helps in compressing the time domain pulse to distinguish the direct wave from the reflected wave and help evaluate the free space antenna factor for site validation of fully anechoic rooms. The antenna pair of ETS-Lindgren Model 3110C and 3180C antennas, simulated with NEC, is subjected to the proposed method with deconvolution filter and Wiener filter. The proposed method is implemented over the measured results of the antenna pair and used for the site validation of a fully anechoic room, based on the simulation results. The Free Space Normalized Site Attenuation Results comply with the 4 dB specification.
Anoop Adhyapak ;
Homogenization modeling of periodic magnetic composite structures
Conventional closed-form homogenizing rules may be not accurate if the contrast of material properties is high, such as the case of ferrite tiles with gaps used in EMC anechoic chambers. A new homogenization method is proposed to handle such extreme cases. It uses the field solution of a single unit cell illuminated by a plane wave incident in the normal direction. By doing this, the physical interactions between adjacent inclusions can be taken into account. Numerical results demonstrate the superiority of the proposed method over conventional closed-form homogenizing rules.
Zubiao Xiong ;
Common RF absorbers evaluations in W-band (75-100 GHz)
This article consists of a collection of slides from the author's conference presentation. Conventional commercial polyurethane absorbers when optimized can achieve about 35-40 dB reflectivity in W band. Latex paint can degrade the absorber performance. Black tips do not significantly improve the performance. Best absorbers are convoluted absorbers (egg crate shaped). Second best are the 3 or 5 pyramids. Flat absorbers with optimized loading can achieve ~30 dB reflectivity in the W band. Wave can penetrate into the absorbers 1 deep. EMC hybrid absorbers generally can only achieve 20 dB reflectivity.
Zhong Chen
Site contributions for radiated emission measurement uncertainties above 1 GHz
Guidance on accounting for site imperfections in the uncertainty evaluation of emissions measurement result is provided by CISPR 16-4-2. Site Voltage Standing Wave Ratio (SVSWR) results from the chamber are used as the basis for estimating the uncertainty contributions due to the site. In this paper, we investigate two aspects of the uncertainty evaluation, and provide a method to estimate the uncertainties based on measured SVSWR data. Firstly, considering that the SVSWR results are under-sampled and under-reported using the current method, is it valid to assume 6 dB as the maximum SVSWR of the chamber Secondly, SVSWR measurements are only performed at the front, left, right, and center (optionally) of the quiet zone (QZ). We study if those locations are adequate representations of the entire QZ performance.
Zhong Chen,
Introduction to the Crafted EMC Operational System
Many companies are looking to reduce their cost by using automated test software as their test process control. If your software controls the test then you open your labor pool. You are no longer restricted to technicians and engineers. There are lower cost resources available. This article was created to help electromagnetic compatibility (EMC) personnel understand EMC automated test software limitations and how to craft an EMC test system to maximize efficiency and minimize cost without sacrificing quality
Jack McFadden
Obtaining total isotropic sensitivity from average fading sensitivity in reverberation chamber
A method of attaining Total Isotropic Sensitivity (TIS) from Average Fading Sensitivity (AFS) in a reverberation Over-the-Air (OTA) test system is provided. First, the Bit Error Rate (BER) curve is measured without reverberation chamber stirring. With the result BER curve, the AFS error rate threshold could be derived from the predefined target BER threshold. Afterwards, the base station power level is lowered down gradually to find the proper power level (i.e. TIS after correction), which reaches the AFS error rate threshold during one reverberation stirring cycle. The lab tests results indicate that the proposed method could obtain the TIS matching the one acquired in the Cellular Telephone Industries Association (CTIA) Authorized Test Lab (CATL) Anechoic Chamber (AC) OTA test system within the measurement uncertainty.
Jun Luo ;
Efficient broadband electromagnetic modeling of anechoic chambers
An efficient method is presented to numerically model anechoic chambers ranging from VHF to microwave frequencies. In this method, an approximate image theory is proposed to improve the accuracy of plane wave assumptions used at lower frequencies. At high frequencies, an efficient image-based ray tracing algorithm is developed which integrates with the approximate image theory seamlessly. Numerical results demonstrate the applications in the analysis of anechoic chambers for both low frequency and high frequency ranges.
Zubiao Xiong ;
A study of the low-frequency coaxial reflectometer measurement procedure for evaluation of RF absorbers' reflectivity
This paper presents a study on the low-frequency coaxial reflectometer measurement procedure. A time domain gating algorithm is developed by ETS-Lindgren and the results are validated after comparing to the Keysight 8753-time domain algorithm. The in-house time gating algorithm is then applied to the simulated reflectivity results of absorbers in reflectometer to the simulation results of the same absorbers with plane wave excitation using finite element method numerical computation. Based on the simulation results, the operable upper frequency limit and the minimum length of the straight coaxial section for the reflectometer are suggested. The errors introduced during measurement due to higher order modes are studied and the permissible limit for the errors is analyzed. The different higher order modes and their effects on field distribution are studied. The impact of the non-uniform field distribution on the absorber reflectivity measurement is also discussed.
Zhong Chen ;
Limitations of the Free Space VSWR Measurements for chamber validations
Free Space VSWR measurement has been the de facto standard method for anechoic chamber performance evaluation for more than 50 years. In this method, a probe antenna is first kept parallel with the boresight angle while traveling along a linear path to record the receive pattern. The probe antenna is then rotated to a different angle to record a standing wave pattern along the same path. Reflectivity, which is used as the chamber performance metric, is calculated as a function of probe rotation angle from the VSWR ripples. Reflectivity obtained this way is shown to be the ratio of the reflections seen by the probe antenna to the incident field at the probe antenna. We demonstrate that reflectivity is affected by the antenna patterns of the probe antenna. Reflectivity measured using a higher gain probe typically yields better (lower) reflectivity level than using a lower gain probe antenna.
Zhong Chen ;
Zhong Chen ;
Customized compact dielectric lens to improve double-ridge horn antenna performance for automotive immunity EMC test
In this paper we present a novel dielectric lens design placed in front of a double ridge horn (DRH) antenna to meet the technical requirements for Automotive Electromagnetic Compatibility (EMC) Immunity tests. ETS-Lindgren 3119 DRH is selected as the reference antenna for its superior wide frequency range. In the new lens design, the shape of the conventional Plano-convex lens is modified to accommodate two seemingly contradictory requirements - to increase the gain of the antenna system to meet a target average field strength (100 V/m @ 2m distance), and in the meantime, to maintain the antenna beamwidth for field uniformity (FU) to be better than 6dB over 80% of the total number of frequency points. Additionally, it is desirable to keep the lens size small to reduce the cost and weight. Both numerical simulation and measurements results are shown, indicating that the proposed lens with DRH antenna is well suited for ISO 11451-2 Automotive Immunity tests.
Zhong Chen ;
The influences of changes in international standards on performance qualification and design of anechoic and hemi-anechoic chambers
Historically, anechoic and hemi-anechoic chamber qualification has been defined in ISO 3745 Annex A. In 2012 an independent standard for anechoic and hemi-anechoic chamber qualification, ISO 26101, was initially released. The presentation will compare and contrast the two standards and their current states. The impact of the changes on existing chambers and future chamber design will be presented.
Douglas Winker and Brian Stahnke
Limitations of symmetry test method for antennas as specified in ANSI C63.5-2006 standard
The ANSI C63.5-2006 standard stipulates a symmetry test to check the antenna balance. The s21 response between two similar antennas, placed at 1m height above the ground plane, is first recorded. The antenna under test is rotated 180 and the response is recorded again. The difference gives the symmetry of the antenna and should be less than 1.0 dB. This paper discusses the limitation of the symmetry test configuration. Specifically, it specifies to place both transmit and receive antennas at a fixed height of 1m above a conducting ground plane, resulting the antenna under test to situate in a null field at some frequencies due to the ground reflection. The effect from the ground plane at the nulls of response distorts the symmetry test result. A new technique is proposed wherein the receive antenna (antenna under test) is placed at 1m height above the ground plane and the transmit antenna scans from 1m to 4m at a step of 0.05 m. The scanning of the transmit antenna helps to eliminate the nulls in the s21 response. Because the antenna under test is always at the fixed height, the measurement yields valid symmetry results for the antenna under test for 1 m height.
An improved method for power and SIR validation on MPAC MIMO OTA system
MIMO OTA testing is becoming a very practical solution to evaluate the wireless terminal performance for high data rate protocols like LTE, LTE-A, 802.11ac,Wi-Fi, etc. Power and SIR (Signal to Interference Ratio) validations are very important for a MIMO OTA system. The results of power and SIR validation tests can confirm that the test settings and correction data from calibration have been applied properly. The CTIA Test Plan for 22 Downlink MIMO and Transmit Diversity Over-the-Air Performance only provides the basic concept of the validation, but does not provide implementation details. This paper provides the detailed background information for the use of linearly polarized reference electric dipoles to validate the power and SIR of a Multi-Probe Anechoic Chamber (MPAC) MIMO OTA system. The entire process can be integrated into an automated measurement procedure that requires only a change of dipole polarization as a manual step. Further, some key parameter settings will be emphasized in this paper.
Jiang Xiao ;
AUTOMOTIVE EMC TESTING: CISPR 25, ISO 11452-2 AND EQUIVALENT STANDARDS
Automotive standards addressing electromagnetic compatibility (EMC) are developed mainly by CISPR, ISO and SAE. CISPR and ISO are organizations that develop and maintain standards for use at the international level. SAE develops and maintains standards mainly for use in North America. In the past, SAE developed many EMC standards which were eventually submitted to CISPR and ISO for consideration as an international standard. As the SAE standards become international standards, the equivalent SAE standard is then withdrawn as a complete standard and reserved for use to document differences from the international standard.
A NOVEL CONCEPT FOR EMC RADIATED IMMUNITY TESTING
The pressure to bring new products to the market, with reduced time to market, high quality and reduced cost, has never been greater. For most electrical and electronic products, the necessity of complying with electromagnetic compatibility (EMC) regulations in order to sell in global markets adds to these pressures. Considering the increased importance of EMC testing for electronic systems, the associated challenges seem to grow simultaneously. These challenges range from increased importance of EMC in the product design phase, to improving EMC test standards for new technologies to developing more efficient instrumentation for EMC testing.
Ammar Sarwar and Vincent Keyser
A Novel Concept for EMC Radiated Immunity Testing using Field Generators
To improve efficiencies and reduce costs in Electromagnetic Compatibility (EMC) testing, a new instrument is developed which merges antennas and amplifiers to overcome difficulties in the traditional EMC Radiated Immunity (RI) setup. A power amplifier is one of the most expensive instruments in an EMC RI test setup. In the conventional setup, according to IEC-61000-4-3, up to 6 dB of the amplifiers rated power is lost for several reasons, e.g., internal cabling within the amplifier, the amplifiers output combiner stage, directional couplers, and cables between the coupler and antenna itself. In this paper a novel concept is presented where active antenna arrays, amplifier stages and directional couplers are combined into one unit, termed a field generator. In this configuration, the E-field (V/m) requirement is emphasized rather than the rated power (W) of the amplifier. Although this concept is not limited to a certain field strength or frequency range, we will discuss the validation of this concept in the 1-6 GHz frequency range to generate 10V/m E-field at a 3m distance to meet the requirements specified in IEC-61000-4-3. The advantages of this concept and a few design challenges in implementation will be discussed. Simulation and measurement results will be presented.
Sound Advice: Ten Things to Know About Acoustical Testing
How well do you know your windows If you have never tested them at an acoustical testing laboratory, you probably dont know them as well as you should. The information gained from acoustical testing is an essential part of architectural specifying and manufacturing and can have an impact on your clients satisfaction, contracts, and bottom line. Testing shows the acoustical performance of your window and easily identifies leaks and underperformance that can lead to unhappy customers and possibly legal actions. So what do you need to know to get your moneys worth out of acoustical testing Read the article for ten tips to ensure a successful acoustical test experience.
Brian Stahnke and Dr. Douglas Winker
Large E Field Generators In Semi-Anechoic Chambers For Full Vehicle Immunity Testing
In this paper the reader will be educated on the fact that the TEM field supported by these structures is not perfectly uniform over the volume occupied by the vehicle at all frequencies, and that the structure will radiate and that it will couple to the chamber enclosure.
Time-Domain Method on Validation of Radiated Emission Test Site Above 1GHz
Recently, it was decided in American National Standards Institute (ANSI) Accredited Standards Committee (ASC) C62 committee that a new standard C63.25 will be drafted to include all site validation procedures within ANSI standards. The time domain sVSWR (TD sVSWR) for site validation above 1 GHz is expected to be included. The invited expert, Mr. Zhong Chen, was interviewed to interpret TD sVSWR briefly and to propose some ideas for the development of site validation.
Time-Domain Method on Validation of Radiated Emission Test Site Above 1 GHz
Interview of ANSI C63 SC1 Chairman, Mr. Zhong Chen, on his experience with Time-Domain Method on Validation of Radiated Emission Test Site Above 1 GHz
Zhong Chen
Application Note 14.001 ETS-Lindgren EMField Generator
In this application note we will address the generation of RF fields in the 1 to 6 GHz frequency range, discuss conventional methods of field generation, and introduce the ETS-Lindgren EMField Generator, a revolution in field generation.
Physical MRI Safety
Magnetic resonance imaging safety can be analogized to a three-legged stool. Anything less than an equal development of three distinct domains - clinical safety, operational safety, and physical safety - makes for a very precarious position.
MR Advancements Call for New Shielding Techniques
When Chris Tomlinson, radiology imaging director at the Children's Hospital of Philadelphia, received complaints from other areas of the hospital about the loud noises from their MR scanners, he know something had to be done about it. "When you put an MR in, if you're not shielding it you can definitely have some complaints from neighbors - they may be on the other side of the wall or even on other floors," he says.
The Future of MIMO Over-the-Air Testing
Wireless radios implementing multiple-antenna or adaptive antenna technologies are pervading LTE and Wi-Fi. These technologies involve some level of interaction with the RF environment, and their dynamic nature means that traditional performance tests that do not adequately reflect the real-world environment will not provide the desired device performance information. In fact, the benefits of some of these approaches can only be tested in an over-the-air environment that reflects an expected use case. This article describes some of the challenges and issues with RF performance tests in a multipleinput multiple-output over-the-air environment, surveys recent approaches used to address these topics, and covers some open areas of current work.
Against All Threats: Protecting America's Power Grid
S&BP asks experts about the best ways to protect electrical infrastructure from physical and cyber attacks, geomagnetic disturbances, an electromagnetic pulse, and radio frequency and microwave weapons.
Designing an Efficient and Effective iMRI Facility
Intra-Operative MRI (iMRI) is quickly becoming the go to technology in the ever evolving integration of various radiologic modalities for invasive and non-invasive patient procedures and treatments. Intra-Operative MRI is defined by the use of an MRI magnet during a surgical or treatment procedure. This can be achieved with a moving magnet that is brought into the theatre or by moving the patient to the room containing the magnet. In both cases, imaging is performed prior to, during and after the surgical or treatment procedure. The real time availability of the high resolution MR images is improving patient outcomes in a widening arena including, but not limited to, neurosurgery, cardiovascular and radiation oncology. This article will provide an overview of current iMRI technology and review design, location, safety and performance considerations to ensure an optimally functioning iMRI facility. Following a successful installation, maintenance guidelines are provided to protect your iMRI investment for years to come of optimal imaging and patient care.
Jim Mueth and Joe Weibler
Surface and internal-temperature versus incident-field measurements of polyurethane-based absorbers in the ku band [amta corner]
Welcome to the first edition of the Antenna Measurement Techniques Association (AMTA) Corner for 2014. As promised, Steve and I are pleased to bring you a summary of AMTA 2013. Chi-Chih Chen, the 2013 AMTA Technical Coordinator, put together a fabulous technical program, with 86 papers organized in 16 sessions, including two poster sessions. Steve and I are pleased to present the top six papers for AMTA 2013, as chosen by the Technical Review Committee, throughout 2014, with the first contribution found after this introduction.
Zhong Chen ;
Real-time,high-tech healthcare. Strategies for designing an efficient intra-operative magnetic resonance imaging space
Intra-operative magnetic resonance imaging is quickly becoming the leading technology in the integration of various radiologic modalities for medical procedures. iMRI refers to the use of an MRI magnet during a surgical or treatment procedure either a moving magnet brought into the theater or by moving the patient to the room containing the magnet. In both cases, imaging of precise locations is performed prior to, during and after the surgical or treatment procedure.
Jim Mueth and Joe Weibler
Reverberation Chambers for Wireless Applications
Owing to the beauty of its statistical behavior, reverberation chambers can be utilized as a measurement environment[1]. In a metallic cavity, numerous resonance modes can be excited. Each mode is induced by standing waves of the electrical fields that resonate with crests and troughs residing spatially. Such field variation due to resonance is seemingly contrary to the concept to establish a constant field with which the measurement can be repeated accurately inside the test volume. Repeatability is the key to the construction of a feasible measurement system. Although each individual resonance mode shows field deviation, the averaged field over sufficient modes can statistically achieve certain field uniformity that the measurement is then repeatable.
Yulung Tang, Shaoyang Cheng, John Xiao
MIMO Wireless Terminals OTA Performance Test Based on Boundary Array Methodology
MIMO antenna technology is commonly used in high speed wireless communication (LTE, WIFI, WIMAX) as well as in high performance radar (MIMO radar). There are more and more wireless terminals with MIMO antenna around the current market. However, there are no current standardized measurement methodologies to evaluate the new technology. The main international standardization organizations, including 3GPP, CTIA and the national organization of China (CCSA), are working to standardize the test methodology. Part of the difficulty in completing a standard of the test method is due to the fact that channel models of multi-path environments complicate the test system to a large degree. Such complexity can be taken into account by the methodology based on boundary array OTA method that makes it a very important evaluation candidate for MIMO OTA performance test. The paper presents a real MIMO OTA test system. After the introduction of boundary array concept, the system calibration is described, including input and output calibration of the entire system. Subsequently, the system validation is examined from several aspects, such as power validation, filed mapping, temporal correlation and so on. Finally, the measurement results of an actual wireless product, with three different antennas, are provided to further elaborate the test methodology. At the end, the current status of the MIMO OTA test methodology standardization is provided to conclude the paper.
Jiang Xiao, Yulung Tang
Surface and Internal-Temperature Versus Incident-Field Measurements of Polyurethane-Based Absorbers in the Ku Band
In recent years, there has been an increased need for testing antennas and radar systems at high power. Since absorbers work by transforming electromagnetic energy into thermal energy, there is a danger that in the presence of high fields, the absorber will reach temperatures that will cause it to ignite. In the present paper, standard polyurethane absorber was illuminated by a conical-horn antenna.
| Zhong Chen and Vince Rodriguez |
EMC Test Laboratory Sofware Program Development: A Proven Process
Asymmetric filter designs are gaining popularity in industry because of their lower cost and size, however, although this design is successful in eliminating common mode signal issues this paper will show that for certain applications such as TEMPEST these filters offer little to no protection. Symmetric filters, although physically larger and more costly due to the use of more components, provide better filtering in these applications.
| Jack McFadden |
On the comparison between anechoic and reverberation chambers for wireless OTA testing
In a previous paper, we have compared pre-compliant and compliant facilities for OTA measurements by carrying out a Round Robin Test on a number of different handsets supplied by one manufacturer. We extend this study here by carrying out OTA measurements on the same handsets in a reverberation chamber and comparing them to our previous anechoic chamber results. This study is important in the context of current developments in wireless standardisation for OTA measurements.
MIMO Device Performance Measurements in a Wireless Environment Simulator
Over-the-air performance testing of MIMO wireless devices requires the simulation of an RF environment similar to that experienced in the real world. There are a number of standardized spatial channel models that are considered acceptable for evaluating MIMO performance of LTE devices. A number of different methods have been proposed for generating MIMO test environments, but the ability of those methods to reproduce a target wireless channel, and the results they produce, vary. There are several methods for evaluating a spatial channel that are useful validation tools if the goal is to produce a specific known environment. This paper will present the results from several of those for different test cases. In addition, a set of reference device antenna systems have been developed to allow one MIMO radio to be tested with antennas designed for "good", "nominal", and "bad" performance. In this way, the ability of a MIMO test system to provide a relative distinction between different levels of device performance may be assessed. This paper will show results of this comparison for different system configurations and channel models and provide an indication of the suitability of these systems for evaluating MIMO device performance.
Michael D. Foegelle
A cone shaped taper anechoic chamber for antenna measurements in the 200 MHz to 18GHz frequency range
Traditionally Taper chambers are constructed using a square based pyramidal shaped taper. The taper is then shaped into an octagon and finally transformed into a cylindrical launch section. This approach is related to the manufacturability of different absorber cuts. This presentation introduces a chamber where the conical shape of the launch is continued through the entire length of the taper chamber. The results of the free space VSWR test over a 1.5m diameter quiet zone are presented at different frequencies in the range from 200MHz to 18 GHz with quiet zone reflectivity levels that exceed -30dB. The conical taper appears to have a better illumination wave front and better QZ levels even at frequencies above 2GHz than the standard traditional approach. The conical taper also appears to be more forgiving to the use of lower gain antennas as the feeds for the taper range when compared with traditional designs.
Vicente Rodriguez
Practical Considerations for Radiated Immunities Measurement using ETS-Lindgren EMC Probes
ETS-Lindgren EMC probes (HI-6022/6122, HI-6005/6105, and HI-6053/6153) use diode detectors for rectifying electromagnetic fields. The probes are calibrated to report continuous wave (CW) root-mean-square (RMS) electric fields. For electric fields with modulations or complex field with multiple frequency components, these probes may not accurately report the instantaneous field values or the true power of the field. For commercial EMC measurements, such as fields with 1 kHz 80% AM as required in IEC 61000-4-3 (EN 61000-4-3), the field readings should be taken with the modulation off (CW or sine wave only).
Steve King
On the MIMO OTA test system
This paper discusses the radio channel modeling for MIMO Over-The-Air testing (OTA). The MIMO OTA is needed for the small devices testing, utilizing multiple antennas. The technologies that utilize multiple antennas are emerging technologies, such as LTE-A and WiMAX evolution (IEEE802.11m), but we also have seen tremendeous increase of MIMO in WLAN type of applications, like IEEE802.11n. This paper discusses also about the testing challenge that MIMO poses for realistic testing.
Jukka-Pekka Nuutinen ;
Determination of sound power level and directionality of reference sound sources in a hemi-anechoic chamber using ANSI S12.5/ISO 6926
Engineering-grade product noise emission testing programs using a hemi-anechoic chamber are qualified, and correction factors are applied to test results, based upon known sound power levels of a reference sound source; i.e., a sound source that has been tested and qualified in accordance with ANSI S12.5/ISO 6926.
Michael C. Black and Einar Gibbens Ristroph
Improvements to broadband Dual Ridge waveguide horn Antennas
Dual-Ridged Horn Antenna (DRHA) are a workhorse in EMC and antenna pattern measurement laboratories. Their broadband capability allows the user to test over a wide frequency ranges without the need to stop the test to change antennas. Recently these antennas came under scrutiny when Burns et al. showed the pattern problems at the upper end of their band. Since their work new models have been introduced that corrected the problems of the DRHA in the 1 to 18 GHz range. In the present paper a CEM software is used to analyze the 200 MHz to 2 GHz design. Gain and pattern are computed. A prototype of the new version is measured. The measured results validate the computed predictions. The result is a DRHA with a smoother gain and pattern. This antenna maintains a single lobe in at a higher frequency than the traditional DRHA.
Vicente Rodriguez
Improving the Performances of a Reverberation Chamber: a Real Case
In a previous measurement campaign it was found that the reverberation chamber (RC) of CISAM EMC Department evidenced anomalous values of the quality factor (Q) - too low to be "right" for a fully aluminum chamber - and moreover, after some use it became absolutely evident that it was too easy to improve - lowering it, of course - the value of the lowest usable frequency (LUF) of this chamber. After some investigations on the chamber materials/components and on the assembly procedures, the authors developed the idea that this strange behavior had to be attributed to the tuners - being the original ones made with somehow absorbing material - and therefore they decided to replace them with new, all metal tuners. In this paper, the results of a calibration campaign on the reverberation chamber after tuner replacement are presented, as well as the results of an emission test on a standard reference source before and after the replacement. The calibration has been done in the frequency range 80 MHz divide 3 GHz, and the emission tests have been performed in the range 100 MHz to 1 GHz, which is exactly the frequency range of the reference radiator used to generate a standard spectrum. The comparison between the results obtained, under the same conditions, with the old and with the new tuners is presented, and the goodness of the assumptions demonstrated: with the new tuners the performances of the chamber have been considerably improved.
Mario Pocai ;
Sound source near field and directionality impacts on hemianechoic chamber qualification
Hemi-anechoic chamber provides a free-field environment for the purpose of precision grade sound power level determinations of devices with tonal emissions. Qualification of hemi-anechoic chambers is of critical concern for both the chamber manufacturers and the end user as it determines free-field performance of the chamber and also yields the largest volume inside the chamber within which a measurement surface can be chosen.
Ankit Chadha, Douglas F. Winker and Einar Ristroph
Pre-Compliance Over-The-Air Performance Testing on Wireless Devices
The use of anechoic chambers for the testing of Over-The- Air (OTA) wireless device requirements such as those regulated by the CTIA has become common practice over the last five years. These facilities allow measurements to be carried out to the degree of accuracy and repeatability required by OTA regulations. However, in most cases OTA chambers become very busy as a result of the number of tests needed to certify each product. Users may therefore encounter throughput issues that delay product development and in the global wireless market of today this can rapidly become a major hurdle to the success of a product.
Elevated sources under hemispherical arrays for product noise testing in hemi-anechoic chambers
Consumer product noise emission testing is often conducted using standardized test methods such as ISO 3744 or ISO 3745. Both standards outline a method of averaging sound pressure levels over a known surface area enveloping the specimen in a free-field environment to determine sound power levels. When the device under test is small (the case for many consumer products), a hemispherical measurement surface in a hemi-anechoic chamber is often used. An assumption is made that the source location is the center of the hemisphere and thus only direct sound energy encounters the measurement surface. In practice, the actual center of measurement surface is located in the floor plane, and the actual product to be tested is placed above the floor plane.
Douglas F. Winker, Ankit Chadha and Einar G. Ristroph
Comparison of two test methods for determination of broadband sound power levels emitted by products: a reverberation chamber method versus a hemi-anechoic chamber method
Two commonly used methods for determining sound power levels a reverberation chamber method and a hemi-anechoic chamber method are compared, with respect to correlation of determined results as well as practical considerations (test time, measurement instrumentation required, and chamber configuration).
Einar Gibbens Ristroph
Complex fit normalized site attenuation using complex magnitude and phase patterns
Due to the diverse designs in log periodic dipole arrays (LPDAs), it is impractical to develop a set of unified correction factors for all types of LPDAs in site attenuation measurements. Even for log antennas with similar frequency ranges and appearances, large variations can be expected in their patterns and phase center positions because of the differences in the feed sections, boom sizes, relative spacings (a) and scale factors (/spl tau/) (Lo, Y.T. and Lee, S.W., 1988). Complex fit normalized site attenuation (CFNSA) has been used successfully by allowing phase centers to move along the centerline of the antenna boom, and by using analytical functions to represent radiation patterns. Approximately 1 dB improvement in antenna factors is observed over the ANSI C63.4/5 model for horizontal polarization. Similar improvements are shown in the vertical polarization. The paper also studies a method that may extend the frequency range by permitting phase centers to vary off-axis, or by using angle dependent phase center positions (which is equivalent to using complex magnitude and phase patterns).
Zhong Chen ;
Complex fit normalized site attenuation for antennas with complex radiation patterns
https://ieeexplore.ieee.org/document/1236714
Zhong Chen ;
Antenna Pattern Measurement: Concepts and Techniques
The first article of this two-part series explores the basic concepts and techniques of antenna pattern measurement and evaluates the benefits and drawbacks of various measurement methods. The concepts relating to near-field and far-field pattern testing are discussed as well. The second article presents the theory and equations governing antenna properties and includes a complete description of a site calibration for pattern-measurement testing
Michael D. Foegelle
Using LISN as an Electronic System EMC Diagnostic Tool
Most EMC engineers consider a Line Impedance Stabilization Network (LISN) to be a device that presents the ac power line of the equipment under test (EUT) with a precise impedance over a designated frequency range. This is the required function of a LISN. A LISN can also be used as...
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- Acoustic Full Line Brochure.pdf
- Audiometric_Brochure.pdf
- Automotive APM Brochure.pdf
- Commercial EMC Brochure.pdf
- E-Motor Brochure.pdf
- EMI Brochure.pdf
- EMP_General_brochure.pdf
- MRI Full Line Brochure.pdf
- Reverb Brochure.pdf
- Reverb Chamber Considerations.pdf
- Services Brochure.pdf
- Test and Measurement in Russian.pdf
- Test_and_Measurement_Full_Line.pdf
- Top 10 Acoustic Testing Considerations.pdf
- Top 10 Anechoic Absorber Considerations.pdf
- Top 10 Considerations for Automotive Chamber Design.pdf
- Top 10 Considerations for MRI Suite Planning.pdf
- Top 10 Considerations for RF and Facility Power Line Filters.pdf
- VAST Handout.pdf
- Why Buy ETS-Lindgren.pdf
- Wireless Solutions.pdf
Demo Programs
| ProbeView II Demo
ProbeView II demo is a self contained program that will simulate the software and a probe collecting data in a simple test environment. Just unzip, install and run the program to view the graphical interface and see the capabilities of ProbeView II.
ProbeView II software leverages the versatile connectivity of the optically connected Holaday field probes to provide industrial hygienists, consultants, EMF and safety professionals with a quick and easy method of collecting, viewing, analyzing and archiving data. The software combined with the HI-4413P Fiber Optic Modem allows a laptop or PC to communicate directly with a field sensor using the RS-232 communication port.
- Acoustic Case Studies
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- Wireless Case Studies
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Intel Bangalore Boosts In-House Acoustic and EMC Test Capabilities
Intel
Download PDF10/01/2013
Industries:AcousticEMC Testing
Automotive Case Studies
TÜV SÜD, Volpiano, Italy
TÜV SÜD, Volpiano, Italy
Download PDF01/27/2021
Industries:EMC TestingAutomotive
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National Automotive Testing and R&D Infrastructure Project (NATRiP)
NATRiP
Download PDF12/01/2018
Industries:AutomotiveEMC Testing
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UTAC CERAM Automotive Test Chamber Evaluates Electromagnetic Capability and Safety Compliance of Automotive Vehicles
UTAC CERAM
Download PDF01/01/2015
Industries:AutomotiveEMC Testing
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EMC Automotive Test Facility Government of India Vehicle Research & Development Establishment (VRDE)
Government of India�Vehicle Research & Development Establishment (VRDE)
Download PDF12/01/2008
Industries:GovernmentAutomotiveEMC Testing
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The Electromagnetic Compatibility Test Chambers at General Motors Proving Ground, Milford, Michigan
General Motors (GM)
Download PDF08/01/2008
Industries:AutomotiveEMC Testing
The New International Center for Automotive Research at Clemson University
Clemson University
Download PDF02/01/2008
Industries:AutomotiveEMC Testing
EMC Testing Case Studies
Kiwa expanding their test capabilities with new EMC Test Facility
KIWA
Download PDF09/09/2021
Industries:EMC Testing
TÜV SÜD, Volpiano, Italy
TÜV SÜD, Volpiano, Italy
Download PDF01/27/2021
Industries:EMC TestingAutomotive
ALTER TECHNOLOGY (T�V NORD GROUP) - Spain
ALTER TECHNOLOGY (T�V NORD Group)
Download PDF10/05/2020
Industries:EMC Testing
Northeastern University Innovation Campus
Northeastern University Innovation Campus
Download PDF07/29/2019
Industries:WirelessGovernmentEMC Testing
Eurofins MET Labs Reverberation Chamber
Eurofins MET Labs
Download PDF05/10/2019
Industries:EMC TestingAutomtive
EMC JAPAN CORPORATION SMART� 100 EMC Reverberation Chamber Test System with Copper Interior
Download PDF04/08/2019
Industries:EMC Testing
National Automotive Testing and R&D Infrastructure Project (NATRiP)
NATRiP
Download PDF12/01/2018
Industries:AutomotiveEMC Testing
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University of Nevada, Reno Opens Newly Upgraded EMC Test Laboratory
The University of Nevada, Reno
Download PDF06/01/2016
Industries:EMC Testing
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New EMC Test System for T�V Rheinland in Vietnam
T�V Rheinland
Download PDF06/01/2016
Industries:EMC Testing
UTAC CERAM Automotive Test Chamber Evaluates Electromagnetic Capability and Safety Compliance of Automotive Vehicles
UTAC CERAM
Download PDF01/01/2015
Industries:AutomotiveEMC Testing
Intel Bangalore Boosts In-House Acoustic and EMC Test Capabilities
Intel
Download PDF10/01/2013
Industries:AcousticEMC Testing
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New Three Meter EMC Chamber Expands TMC's Test Capabilities
Telecommunication Metrology Center (TMC)
Download PDF04/01/2010
Industries:EMC Testing
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Bureau Veritas Expands its Littleton, Massachusetts Laboratory
Bureau Veritas
Download PDF07/01/2009
Industries:EMC Testing
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Boeing, St. Louis Selects ETS-Lindgren for Custom All-Welded Chamber Installation
Boeing
Download PDF07/01/2009
Industries:EMC TestingGovernment
.jpg)
Intertek Expands EMC Lab with New 10 Meter Chamber
Intertek
Download PDF05/01/2009
Industries:EMC Testing
EMC Automotive Test Facility Government of India Vehicle Research & Development Establishment (VRDE)
Government of India�Vehicle Research & Development Establishment (VRDE)
Download PDF12/01/2008
Industries:GovernmentAutomotiveEMC Testing
The Electromagnetic Compatibility Test Chambers at General Motors Proving Ground, Milford, Michigan
General Motors (GM)
Download PDF08/01/2008
Industries:AutomotiveEMC Testing
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The EMC Test Center for Excellence at Ingenium Testing
Ingenium Testing
Download PDF04/01/2008
Industries:EMC TestingGovernment
The New International Center for Automotive Research at Clemson University
Clemson University
Download PDF02/01/2008
Industries:AutomotiveEMC Testing
Government Case Studies
Northeastern University Innovation Campus
Northeastern University Innovation Campus
Download PDF07/29/2019
Industries:WirelessGovernmentEMC Testing
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Tapered Antenna Chamber Offers Plane Polar Near and Far Field Testing
India Space Research Organization (ISRO)
Download PDF01/01/2016
Industries:Government
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Electromagnetic Test Center at the Korea Agency for Defense Development
Boeing
Download PDF01/01/2015
Industries:EMCGovernment
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Multi-Purpose Tapered Chamber at the National University of Singapore Enables Far-Field and Spherical Near-Field Test Measurements Over an Extended Frequency Range
Temasek Laboratories (T-Lab) of the National University of Singapore (NUS)
Download PDF05/01/2011
Industries:WirelessGovernment
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PIM Chamber Installed at Lockheed Martin Company
Lockheed Martin
Download PDF02/01/2011
Industries:Government
Boeing, St. Louis Selects ETS-Lindgren for Custom All-Welded Chamber Installation
Boeing
Download PDF07/01/2009
Industries:EMC TestingGovernment
EMC Automotive Test Facility Government of India Vehicle Research & Development Establishment (VRDE)
Government of India�Vehicle Research & Development Establishment (VRDE)
Download PDF12/01/2008
Industries:GovernmentAutomotiveEMC Testing
The EMC Test Center for Excellence at Ingenium Testing
Ingenium Testing
Download PDF04/01/2008
Industries:EMC TestingGovernment
Healthcare Case Studies
MOUNT SINAI UNION SQUARE, NEW YORK CITY, NEW YORK
Mount Sinai Union Square New York, New York
Download PDF12/17/2020
Industries:Healthcare
Leading Hospital � Hong Kong
Leading Hospital - Hong Kong
Download PDF03/11/2020
Industries:Healthcare
iMRI Suite - Southeastern US
iMRI Suite - Southeastern US
Download PDF07/01/2019
Industries:Healthcare
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GE Selects ETS-Lindgren As Preferred Partner for RF Shielded Enclosures
General Electric (GE)
Download PDF01/01/2018
Industries:Healthcare
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Intra-Operative MRI Facility at Houston Methodist Hospital
Houston Methodist Hospital
Download PDF11/01/2016
Industries:Healthcare
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Northwest EMC�s New Test Laboratory in Minnesota Now Available for Wireless, Medical and Consumer Electronic Product Testing
Northwest EMC
Download PDF04/01/2009
Industries:WirelessHealthcare
IT Case Studies
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Wireless Case Studies
Northeastern University Innovation Campus
Northeastern University Innovation Campus
Download PDF07/29/2019
Industries:WirelessGovernmentEMC Testing
.jpg)
Wi-Fi Alliance and ETS-Lindgren Are A Perfect Team Addressing Wireless Test Technology
Wi-Fi Alliance
Download PDF08/01/2015
Industries:Wireless
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EMT Labs Offers Wireless OTA Performance Verification
Electro Magnetic Test, Inc.
Download PDF06/01/2015
Industries:Wireless
Antenna Measurement System Enhances R&D Capabilities for AAC
AAC SINGAPORE
Download PDF01/01/2014
Industries:Wireless
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Gonzaga University Smart Antenna and Radio Lab
Gonzaga University�
Download PDF07/01/2011
Industries:Wireless
Multi-Purpose Tapered Chamber at the National University of Singapore Enables Far-Field and Spherical Near-Field Test Measurements Over an Extended Frequency Range
Temasek Laboratories (T-Lab) of the National University of Singapore (NUS)
Download PDF05/01/2011
Industries:WirelessGovernment
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AT4 wireless Boasts World's First WiMAX Forum Designated Certification Laboratory
AT4 wireless
Download PDF10/01/2009
Industries:Wireless
Northwest EMC�s New Test Laboratory in Minnesota Now Available for Wireless, Medical and Consumer Electronic Product Testing
Northwest EMC
Download PDF04/01/2009
Industries:WirelessHealthcare
First WiMAX Forum Designated Certifica0tion Laboratory in Asia at Advance Data Technology (ADT) Corporation in Taiwan
Advance Data Technology (ADT) Corporation
Download PDF12/01/2008
Industries:Wireless
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New Wireless Test System at TMC Beijing
Telecommunication Metrology Center (TMC)
Download PDF12/01/2008
Industries:Wireless
Corporate Overview
Media Contact
Janet O'Neil
Sales & Marketing
ETS-Lindgren
+1-512-531-2676
janet.oneil@ets-lindgren.com