ETS Lindgren

Whitepapers from ETS Lindgren

5G Millimeter Wave Devices: The Impact on EMC Compliance Tests

This whitepaper details the challenges presented by 5G millimeter wave (mmWave) devices to existing EMC compliance testing procedures. The authors highlight that while standards evolution typically lags deployment, 5G's use of both Frequency Range 1 (FR1 – sub-6 GHz) and Frequency Range 2 (FR2 – up to 52.6 GHz) necessitate significant adaptations to current methods. Key concerns revolve around the transition from conducted measurements due to complex antenna arrays in FR2, and the impact of near/far field boundaries at higher frequencies like 60GHz where wavelength is only 5mm. The paper emphasizes that accurate testing requires considering antenna placement, beamwidth (down to ~10 degrees for FR2), path loss variations – which can exceed 73dB at 3 meters and 39 GHz – and the limitations of current measurement systems. Relevant standards mentioned include ITU-T K Supplement 10, CISPR, FCC Part 30, and ETSI regulations focused on EIRP (Effective Isotropic Radiated Power) and TRP (Total Radiated Power).

5G Testing

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Chambers for the Evaluation of Vehicle Mounted Antennas

The document examines the evaluation of vehicle-mounted antennas in anechoic chambers, focusing on floor treatments and their influence on chamber performance. It compares different floor conditions (PEC, lossy, absorber-lined) and measures ripple magnitude variation for horizontal and vertical polarizations. The analysis highlights resonant peaks and reflections from various surfaces within the chamber.

AntennasAnechoic Chamber

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Complex Fit Normalized Site Attenuation for Antennas with Complex Radiation Patterns

This paper investigates improvements to Normalized Site Attenuation (NSA) calculations, specifically proposing a Complex Fit NSA (CFNSA) method that accounts for complex antenna patterns like those found in Log-Periodic Dipole Arrays (LPDAs). The authors address limitations of the ANSI C63.5 standard’s cosine pattern approximation, finding it inadequate above 500 MHz. They explored higher-order polynomial functions to model LPDA patterns – a fourth order fit F(θ) = R₀ + a₁cos(bθ) + a₂cos²(bθ) + a₃cos³(bθ) + a₄cos⁴(bθ) was found capable of realistically fitting measured H-plane patterns up to 2 GHz. The CFNSA method, using this pattern formulation and a Genetic Algorithm for parameter optimization on test data from two LPDAs (200MHz - 2GHz and 200MHz - 1GHz), demonstrated reduced antenna factor variations – below 1dB from 1-2 GHz versus ~1.5 dB with simpler models.

EMI / EMC TheoryAntennas

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Customized Compact Dielectric Lens to Improve Double-Ridge Horn Antenna Performance for Automotive Immunity EMC Test

This document discusses the use of a customized compact dielectric lens to improve double-ridge horn antenna performance for automotive immunity EMC tests. It presents simulation results and experimental data demonstrating improved field uniformity and reduced power requirements. This custom solution enhances the setup’s ability to meet ISO 11451-2 standards for automotive EMC immunity testing.

AntennasAutomotive EMCImmunity Testing

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EMC Antenna Fundamentals

This paper provides a fundamental overview of antenna selection and terminology relevant to Electromagnetic Compatibility (EMC) testing. It distinguishes between radiating devices like antennas and non-radiating field generators such as TEM cells, highlighting that EMC applications primarily utilize antennas for radiated emissions, immunity, site qualification, or reverberation chamber excitation. The article details concepts like directivity (2.14 dBi for a half-wave dipole compared to an isotropic source), gain (often including mismatch factor in practical EMC use), and crucial antenna characteristics such as VSWR, return loss (e.g., 9.5dB for VSWR=2:1) and antenna factor – relating incident electric field to load voltage. Finally, it outlines the function and benefits/drawbacks of various antenna types commonly used in EMC testing including loop antennas (20Hz-30MHz), rod antennas (30Hz-50 MHz), dipoles, biconical antennas (20MHz–300MHz) and their relevance to standards like MIL-STD 461 and ANSI C63.5.

Antennas

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EMC Antenna Parameters and their Relationships

This paper by John D. M. Osburn of EMC Test Systems provides a rigorous mathematical derivation of two fundamental EMC antenna parameters: the Antenna Factor (AF) and the Transmit Antenna Factor (TAF). The AF, expressed as the ratio of incident electric field strength to the voltage at the antenna terminals (AF = E/V_L), is the primary parameter used in radiated emissions testing to convert measured voltages into field strength values. Starting from basic antenna theory — effective aperture, the Friis transmission formula, and Ohm's Law — the paper derives the AF in a 50-ohm system as AF = 9.73 / (λ√G_r), and its dB equivalent: AF = 19.8 - 20·log(λ) - 20·log(G_r). The TAF is derived as the complementary parameter for radiated immunity testing, relating the input voltage of a transmitting antenna to the electric field it generates at a known distance. The paper demonstrates that while AF and TAF share the same units (m⁻¹), they are neither identical nor reciprocal — their relationship depends on antenna gain and the distance at which calibration is performed. A conversion formula between the two is provided, valid under ground-plane or semi-anechoic conditions. The paper's intent is explicitly educational: these parameters are widely used daily in EMC labs but their derivations are rarely understood. By grounding the formulas in first principles, the author provides engineers with the conceptual foundation to understand why the values are what they are and how to apply them correctly across both emissions and immunity test setups.

AntennasAntenna FactorEMI / EMC Theory

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Efficient Broadband Electromagnetic Modeling of Anechoic Chambers

This white paper discusses electromagnetic modeling of anechoic chambers used in EMC testing. It highlights that while full wave solvers such as FEM, FDTD, MoM, and MLFMM can accurately solve Maxwell's equations, they often face practical limitations due to high memory and time requirements for larger chambers and higher frequencies. Therefore, the white paper emphasizes the use of ray tracing methods, which are more efficient. The ray tracing method involves modeling electromagnetic field reflection correctly by using a general approach that accounts for polarization and decomposes fields into components parallel and perpendicular to the plane of incidence. This method is noted for its efficiency while offering better accuracy at lower frequencies compared to traditional decomposition techniques when near-field effects are significant. The white paper also presents numerical examples demonstrating NSA prediction and free-space VSWR reflectivity analysis using this approach.

EMI / EMC TheoryAnechoic Chamber

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Free Space Antenna Factor Computation Using Time Domain Gating and Deconvolution Filter for Site Validation of Fully Anechoic Rooms

The document details free-space antenna factor computation using time-domain gating and deconvolution filters for site validation of fully anechoic rooms. It complies with CISPR 16-1-4:2010 standards to ensure minimal reflections from chamber walls. Simulation results confirm compliance with the ±4 dB specification for normalized site attenuation.

Antenna FactorAntennasAnechoic Chamber

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Modeling of Tapered Anechoic Chambers

This paper presents a hybrid numerical method for simulating electromagnetic fields within tapered anechoic chambers, particularly focusing on improving accuracy at lower frequencies (below 500 MHz) where traditional ray tracing methods like SBR struggle. The approach combines Finite Element Method (FEM) modeling of the chamber throat – including the source antenna - with Floquet mode analysis to represent absorber arrays as virtual surfaces and subsequent application of the Shooting and Bouncing Ray (SBR) method for the remainder of the chamber. FEM calculates equivalent currents at the throat interface, which serve as sources for SBR. The authors validated this technique against full-wave simulations using ANSYS HFSS for a 54m chamber (42m tapered, 12m rectangular) with pyramidal absorbers on all walls and observed good agreement in field distribution, including longitudinal ripples and transverse amplitude tapering from 100MHz to 300 MHz.

Anechoic ChamberEMI / EMC TheoryEMI / EMC Simulation

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Multi-Purpose Anechoic Chambers - EMC (SAR/FAR) to Antenna Measurements

This paper investigates the versatility of a 3m semi-anechoic chamber (SAR 3) – specifically an ETS-Lindgren model with internal dimensions of 9m x 6m x 6m – in meeting increasingly diverse EMC standards across various industries including automotive, aerospace, and telecommunications. The authors detail how the chamber can be adapted for both Radiated Immunity/Emission testing below (30 MHz - 1 GHz) and above (up to 18GHz) 1 GHz, conforming to standards like EN 50147-2, IEC 61000.4.3-2002, and the evolving CISPR 16-1-4 for Fully Anechoic Rooms (FARs). Key findings demonstrate compliance with NSA & FSNSA tests showing deviations within ±4dB across critical frequencies, as well as quick conversion times (under 30 minutes) between SAR and FAR configurations by utilizing removable ferrite panels. The paper also addresses challenges related to antenna selection (log-periodic vs. horn) and cable performance above 1 GHz, highlighting the limitations of current transmission loss validation methods.

AntennasAnechoic Chamber

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Reverberation Chambers: Design and Construction Considerations for Aerospace and Military Test Requirements

This whitepaper details design and construction considerations for reverberation chambers used in aerospace and military EMC testing, focusing on achieving high field strengths (up to 7200 V/m from 4-6 GHz as required by DO-160 Category L). Reverberation chambers utilize internal reflections created by rotating tuners to achieve statistically isotropic fields, offering advantages over other test methods like lower cost and higher field-to-input power ratios. Key construction aspects discussed include modular panel design (using materials like galvanized steel, copper, and aluminum), the importance of chamber volume for frequency range, seismic bracing (up to Zone 4), and shielding performance targets exceeding 100 dB up to 10 GHz. Proper installation and certification tests (MIL-STD-285, IEEE-299, DO-160F/G) are crucial for ensuring accurate and repeatable results.

Reverberation ChambersMilitary and Aerospace EMC

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Latest news for ETS Lindgren

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ETS-Lindgren Brings Its Latest EMC and Wireless Solutions to EMC/China 2026

June 18, 2026

ETS-Lindgren will exhibit at EMC/China 2026 in Shenzhen on June 25–26, showcasing its latest EMC, 5G, OTA, automotive, and wireless test solutions at Booth #162.

ETS‑Lindgren to Exhibit at Chicago IEEE EMC MiniSymposium and EMC Fest 2026

April 25, 2026

ETS‑Lindgren will exhibit at two IEEE EMC events in May 2026 — the Chicago EMC MiniSymposium on May 5 in Naperville, IL, and EMC Fest 2026 on May 7 in Livonia, MI. The company will showcase its EMC and automotive EMC testing solutions.