Analysis of the coupling of electromagnetic pulses into shielded enclosures of vulnerable systems

In order to predict the immunity to electromagnetic interference of vulnerable systems, not only the electronic system but also its enclosure has to be taken into consideration. In this work, the coupling behavior of electromagnetic pulses (EMP) and continuous wave (CW) signals into the shielded enclosure of a generic system is investigated by metrological and numerical methods. Since this enclosure forms an unwanted or parasitic cavity resonator, the enclosure`s resonance behavior as well as the characteristic quantities, i.e., the resonance frequencies and corresponding quality factors are of great interest, too. The usage of an optical field sensor reduces the influence of the measuring setup on the investigated system and thus, enables the analysis of the enclosure's resonance behavior, which delivers revealing information about the dependence of the quality factor on the aperture size of the enclosure

Experimental Testing of a Metamaterial Slow Wave Structure for High-Power Microwave Generation

Experimental Testing of a Metamaterial Slow Wave Structure for High-Power Microwave Generation by Kevin Aaron Shipman B.S., Exercise Science, University of New Mexico, 2008 A.S., Mathematics, San Juan College, 2014 M.S., Electrical Engineering, University of New Mexico, 2018 Abstract A high-power L-band microwave source has been developed using a metamaterial (MTM) to produce a biperiodic double negative slow wave structure (SWS) for interaction with an electron beam. The beam is generated by a ~700 kV, ~6 kA short pulse (~ 10 ns) electron beam accelerator. The design of the metamaterial SWS (MSWS) consists of a cylindrical waveguide, loaded with alternating split-rings that are linearly arrayed axially down the waveguide. The beam is guided down the center of the rings by a strong axial magnetic field. The electrons interact with the MSWS producing electromagnetic radiation in the form of high-power microwaves (HPM). The Power is extracted axially by a conical horn antenna. Microwave generation is characterized by an external cutoff waveguide detector, as well as the radiation pattern of the RF. Mode characterization is performed using a neon bulb array, where the bulbs are lit by the electric field in such a way that the pattern in which they are excited resembles the field pattern. A time integrated image is of this pattern is taken by an SLR camera. Since the MTM structure has electrically small features, breakdown within the device is a concern. Therefore, a fiber-optic-fed, sub-ns photomultiplier tube array diagnostic has been developed and used to characterize light emission from breakdown. A description of the diagnostic developed and experimental results will be presented

Design for Electromagnetic Compatibility--In a Nutshell

This open access book provides practicing electrical engineers and students a practical – and mathematically sound – introduction to the topic of electromagnetic compatibility (EMC). The author enables readers to understand better how to overcome commonly failed EMC tests for radiated emission, radiated immunity, and electrostatic discharge (ESD), while providing concrete EMC design guidelines. The book also presents an overview of EMC standards and regulations and how to test for a global market access

Evaluation of Lightning Induced Effects in a Graphite Composite Fairing Structure

Defining the electromagnetic environment inside a graphite composite fairing due to lightning is of interest to spacecraft developers. This paper is the first in a two part series and studies the shielding effectiveness of a graphite composite model fairing using derived equivalent properties. A frequency domain Method of Moments (MoM) model is developed and comparisons are made with shielding test results obtained using a vehicle-like composite fairing. The comparison results show that the analytical models can adequately predict the test results. Both measured and model data indicate that graphite composite fairings provide significant attenuation to magnetic fields as frequency increases. Diffusion effects are also discussed. Part 2 examines the time domain based effects through the development of a loop based induced field testing and a Transmission-Line-Matrix (TLM) model is developed in the time domain to study how the composite fairing affects lightning induced magnetic fields. Comparisons are made with shielding test results obtained using a vehicle-like composite fairing in the time domain. The comparison results show that the analytical models can adequately predict the test and industry results