In this task, the potential of cold spraying for the generation of EM shielding coatings on polymers will be investigated. Spray formulations will be developed that optimally balance superior electromagnetic shielding performance with durability during mechanical and thermal loading, good scratch resistance and adhesion as well as enable a sustainable end-of-use option. Thereby, apart from more traditional metallic coating formulations also coatings including magnetic nanoparticles or doped with self-healing polymers will be investigated as well as polymer surface pre-treatments to optimize adhesion and to facilitate matrix-coating separation after end-use. ption
When making predictions about EMC performance, it is crucial to know the electromagnetic properties of materials – in particular, lossy materials intended to decrease radiation by absorbing incident electromagnetic energy. Usually, the ‘shielding effectiveness’ (SE) is measured. There are two problems with the current approach: 1) The shielding effectiveness is a resulting parameter from the material’s constituent parameters (complex permittivity and permeability), resulting in a lack of information for predictive modelling and 2) most techniques are destructive, requiring accurate sample shaping to obtain an acceptable measurement uncertainty. In this project, we will develop neat methods for material characterization, covering a large frequency band (100MHz-10GHz), to measure the complete constituent without modifying the material under test. While broad-band methods for material characterization at frequencies are relatively well established for dielectric materials, convenient methods for characterization of magnetic materials are much rarer and often cumbersome. This novel (in-situ) material characterization method applied to a set carbon-fibre-filled plastic produced with specialists from DEM. To overcome the intrinsic connection limitations in such fibre composites, synergistic filler combinations will be exploited. mple Description
To be able to achieve the objectives set forward by the EU Green Deal, mobility will go through several significant changes in the coming decade. Two parallel connected evolutions are the rise of fully electric cars and of autonomous cars. On the one hand, fully electric cars will inevitably comprise a lot of power electronics. On the other hand, autonomous cars heavily rely on sensors, actuators, and programmable electronics. Power electronics is inevitably a source of heavy electromagnetic disturbances, mainly in the very-low frequency range. Sensors, actuators, and programmable electronics are all increasingly sensitive to low-frequency electromagnetic disturbances. Unfortunately, low-frequency electromagnetic disturbances are very hard to confine by shielding and proper characterization methods are lacking. Especially in that frequency range, shielding effectiveness values heavily depend on the specific source, the source orientation, the distance between source and shield, etc. In this task, the DR will, starting from the characterization method described in IEEE 299, develop, and compare several SE characterization methods to characterize the shielding properties of materials at very-low-frequencies. A sound theoretical background will allow to give the right interpretation to the obtained SE values for use of the material in practice.
Capacitive touch-based control applications are increasingly used on-board and are especially sensitive to harsh EM fields and other parasitic environmental effects like temperature drifts and humidity. DR4 will develop an active shield method to increase the robustness and immunity of these safety-critical applications. The sensitive frequencies of the device and the possibilities of eliminating these weaknesses will be investigated. Design solutions and their trade-off in term of performances vs SSbD approach will be documented. Selected designs will be verified using simulation tools (CST Studio Suite) and resulting prototypes will be manufactured and tested within the EMC laboratories in TBU (semi-anechoic chamber) and at beneficiary UoY (reverberating chamber). U support prototyping, NXP-CZ provides real-life applications: MCU devices (i.e., Kinetis MKE1x series), with on-chip capacitive touch sensing (TSI) peripheral supporting one or more Active Shield output pins, which can be enabled during the TSI scans
There is a gap between conducted EMI (waveform control and filter) and radiated EMI (shielding), particularly for wide band gap devices-based power converters. Current shielding effectiveness standards focus on the measurement of shielding effectiveness in the frequency domain, though some work has been done on defining and characterizing shielding in the time domain. There appears to be nothing in the literature relating to time domain on-board shielding. This task aims to further the understanding of on-board shielding for power electronic and provide tools to allow engineers to optimize this shielding. An innovative strategy to shield on-board EMI generated by power-electronic equipment will be explored. It consists in a holistic shielding technique including both software and hardware. This will enable a trade-off between waveform control (complexity and efficiency) and shielding techniques (mass and cost) in the overall on-board design. This trade-off will be assessed with respect to the SSbD approach.
With the increasing use of higher frequencies in electronic components with ever smaller footprints, it becomes more difficult to confine electromagnetic (EM) emissions. This is especially true for systems that comprise very different types of circuits close to each other, e.g., autonomous vehicles implementing high power frequency drives and very high frequency radars. Containing the EM emissions within a confined space is mostly achieved by implementing shielding materials like board level shields, gaskets, etc. Despite their efficiency, some downsides exist (e.g., heat conduction, space, etc.) by implementing these materials. Another solution is to employ specific absorbers on the radiating parts directly to decrease their emissions. There are however not many easy-to-use characterization methods to measure the shielding capabilities of absorbers. Also, the absorption of those materials would depend on the type of EM source. In this task, a characterization method will be developed to measure the absorption of multiple material under different EM conditions. The measurement results of these materials
This task is about investigating the SE of real complex 3D structures as opposed to the currently used, overly simplified techniques that lead to severe overestimations and unnecessary performance degradation caused by improper characterization and implementation of interconnects. Even the most high-tech industries are forced to manufacture several prototypes and perform tests, because the actual performance of interconnection techniques is unknown. A major factor is also the lack of interaction between material engineers, mechanical engineers’ electromagnetic engineers. The SE of a complex structure is only as good as its weakest point therefore it needs to be characterized to expose the bottlenecks and adapt its design to balance and optimize the performance overall. This task focuses on the characterization of various interconnect types that will serve as a tool for estimating and optimizing their SE following the steps: modelling, validation, correction, and conversion to parameters usable by industry depending on the application ranging from small full-metal, composite and embedded plastic structures, interfaces, feedthroughs, to complete ships, rooms, or buildings, including monitoring the effects of breaching, corrosion, and deterioration over time.
Cables are at the heart of the revolution occurring in our electronic and electric systems for mobility. They are the key propagator of EMI: they catch, radiate, and amplify noise. Parasitic EM noise propagates in a cable as a current, or around it as EM waves. This parasitic energy exchanged between a cable and its environment has never been entirely and simultaneously grasped, either computationally or experimentally. The first is burdened by computational complexity, the second is limited by the spatial directivity of measuring techniques resulting in a SE define per unit length, based on an experimental transfer impedance which differs from its equivalence in real- life installations. In this task an accurate measurement procedure will be developed to measure the energy exchange through the shield of a cable. The Reverberating Chamber (RC) is the most accurate means to measure a “radiation efficiency” because it allows isotropic device measurements. There is no need for device alignment or three-dimensional scans, as there would be in an anechoic chamber.
Conventional shielding effectiveness (SE) measurements do not consider the variability in the SE of a non-reverberant enclosure. In this task we will develop more accurate shielding metrics, modelling and measurement techniques that will allow the real-world shielding effectiveness of non-reverberant enclosures with contents to be quantified. This will allow engineers to predict the risk of EMC failures and optimise the shielding design of their equipment resulting in a reduced design overhead and therefore lower costs in terms of both materials and time more accurately. Other impact on the SSbD KPIs will be quantified as well. We have previously shown that the SE of an enclosure is not an intrinsic property of the enclosure itself. It depends on the transmission cross-section (TCS) of the enclosure apertures as well as the absorption cross-section (ACS) of the enclosure contents. In this work we would aim to measure the TCS of an enclosure and the ACS of its contents in a statistical sense so that the SE of an enclosure can be statistically quantified.
This task addresses the fundamental concept of shielding achieved by reflection and/or absorption, the corresponding trade-offs considering the material properties, design, and implementation, and performance evaluation methods of the sample, also in its designated application with a strong focus on reverberant enclosures such as airplanes and cars. These reverberant enclosures are cavities with locally (much) higher field strength. Shielding (reflection) measures are much less effective than absorption. However, the currently available absorption materials have disputable stable performance, and the materials are used in a try-and-error process. The DR will focus on the selection of materials (e.g., carbon-fibre filled plastics, ferrite, sprayed-cold composite, or metal, also as a frequency selective surface (FSS)), trade-offs considering e.g., weight, volume, shape, frequency range and selectivity, implementation type (e.g., coating, paint, gasket/rivet/screw, FSS mesh), design fit and integration in the designated application, as well as cost/performance trade-offs to ensure.
DR11 will develop 3D embedded shielding solutions using layer-by-layer approaches. It has already been realized that some electromagnetic shielding polymer formulations exhibit printability. However, this technique has not yet been exploited to incorporate embedded shielding solutions that provide local shielding within larger structures. Novel material formulations and modified 3D printing methods (CTIC) will allow to achieve the required trade-off between shielding efficiency and processibility while maintaining sufficient resolution. Electromagnetic propagation modelling will be used to design demonstrator materials with local shielding capability at TU/e
Time-domain measurement methodologies to measure simultaneously the electric and magnetic field have been employed in the past to measure Unmanned Air vehicles (UAV). Moreover, simulations and measurements have been combined to characterize challenging materials like composite or 3D printed conductive. DR12 will take up the challenge of investigating (in-situ) time-domain techniques which would enable a simultaneous link to be made between Electric and Magnetic field. S/he will validate these techniques on Board Ships (THALES) and with Innovative Shielding Material developed at TU/e.