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DO-160 Simulations

In the measurement, a double exponential current waveform resembling lightning component A, but with 400 mA amplitude, is injected onto the shield of the cable. The cable shield was grounded to an aluminum sheet placed 2 inches below the cable, such that the current path was from the cable shield to the aluminum sheet, back to the generator ground. The open circuit voltage (VOC) was then measured at the end of the cable opposite the injection point.

Picture of system level e3 flow

System Level E3

Systems Level Perspectives for E3 and EMI Control by Tim McDonald Recently, I was invited to give a workshop talk in the IEEE EMC 2014. The entire session was interesting, and there were many good discussions afterward. My presentation is below: A key challenge for system level E3 (electromagnetic environmental effects) engineers is in translating […]

aircraft hirf

Visualizing HIRF

Visualizing HIRF Fields Inside Aircraft By Jennifer Kitaygorsky High intensity radiated fields (HIRF) can come at an aircraft from any direction, and enter the aircraft through apertures, seams and gaps. Some aircraft systems may be susceptible to this type of EM radiation, and visualizing HIRF fields can further our understanding about what’s happening inside an […]

multi conductor harness cross section

Braided Shields

Coupling through braided shields is determined by the transfer impedance, an intrinsic property of all cable shields. Here, we compare transfer impedance measurements of braided shields and various cables with ideal (round) and non-ideal (flattened) geometries.

Nanomaterials for Lightning

SAMPE 2014

Novel nanomaterials for lightning protection by Tim McDonald EMA attended SAMPE 2014 in Seattle. There were many great papers presented, and we had great discussions with attendees. In the following section, we describe EMA’s paper presented at the conference. Advanced Electromagnetic Simulation Techniques for Novel and Modern Materials in Aerospace Composites In recent years, composite […]

EM Emissions

EM Emissions

By Bryon Neufeld EMA has extensive experience in electromagnetic emissions (EM emissions) from a wide variety of sources, including cables and individual electronic components such as in aircraft avionics or wireless communications. One example of this work is in our calculation of the far-field EM emissions generated by internal electronics units in a wireless communications station.  […]

Using Hilbert Transform, the time domain data is reconstructed

EMC Signal

In electromagnetic systems, it is often easy to measure the magnitude response but the phase response can be difficult to obtain.  An engineer or scientist may have access to the magnitude response of a measurement in frequency space, and wish to obtain the phase or reconstruct the time domain signal. Fortunately, there are theoretical tools […]

When current flows through parallel conductors, there is a force

Magnetic Forces

Whenever lightning current flows on two parallel conductors, there is a force that tends to compress the two into each other. In some cases, this can lead to damage. In looking at the Magnetic Force calculations in the classic, Lightning Protection of Aircraft (self-published by Lightning Technologies division of NTS), we noticed that the equation […]

Three kinds of carbon nanotubes

Nano and Lightning

Tim McDonald of EMA recently gave a talk at the Graphene Commercialization and Applications conference. The slides from the talk are below: This is an embedded Microsoft Office presentation, powered by Office Online.

DO-160 Simulation

DO-160 Simulation

One of the challenges of electromagnetic modeling on systems (aircraft, wind turbines, etc.) is understanding the induced transients on individual pins. It is reasonably straightforward to model the currents that are induced on overall cable bundles. However, it is the current and voltage on individual conductors that often matters to system designers. The geometry is […]

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