Sökning: "electromagnetic propagation"

Visar resultat 1 - 5 av 78 avhandlingar innehållade orden electromagnetic propagation.

  1. 1. Intentional electromagnetic interference (IEMI) : Susceptibility investigations and classification of civilian systems and equipment

    Författare :Daniel Månsson; Rajeev Thottappillil; Mats Bäckström; William Radasky; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electromagnetic compatibility; Intentional electromagnetic interference; High power electromagnetic; Other engineering physics; Övrig teknisk fysik;

    Sammanfattning : This PhD thesis addresses the threat posed to society by sources that can produce high power electromagnetic pulses (HEPM) and be used maliciously to disturb or damage electronic equipment. The vulnerability from intentional electromagnetic interference (IEMI) has increased in the recent decades due to the widespread dependence of the civil society on sensitive electronic systems and proliferation of radiation sources. LÄS MER

  3. 2. Electromagnetic Interference in Distributed Outdoor Electrical Systems, with an Emphasis on Lightning Interaction with Electrified Railway Network

    Författare :Nelson Theethayi; Rajeev Thottappillil; Farhad Rachidi; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical engineering; Electromagnetic Compatibility EMC ; Lightning; Lightning Protection; Transmission Lines; Electromagnetic Wave Propagation; Underground Cables; Grounding; Electromagnetic Transients; Electromagnetic Interference; Shielding Effectiveness; Railway Systems; Elektroteknik; elektronik och fotonik; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

    Sammanfattning : This thesis deals with the electromagnetic compatibility (EMC) problems of distributed electrical networks, especially that caused by lightning to electrified railway. Lightning transients were found to damage important devices that control train movements, causing traffic stoppage and delays. LÄS MER

  4. 3. Nonlinear interaction and propagation of gravitational and electromagnetic waves in plasmas

    Författare :Martin Servin; Gert Brodin; Lennart Stenflo; Demetrios Papadopoulos; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical physics; general relativity; plasma; gravitational waves; electromagnetic waves; nonlinear; wave interaction; wave propagation; Teoretisk fysik; Physics; Fysik; teoretisk fysik; Theoretical Physics;

    Sammanfattning : Gravitational waves and electromagnetic waves are important as carriers of energy and information. This thesis is devoted to the study of the propagation and interaction of these waves in plasmas, with emphasis on nonlinear effects and applications within astrophysics. LÄS MER

  5. 4. Transient electromagnetic pulse propagation in temporally dispersive materials

    Författare :Igor Egorov; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Green functions; direct scattering; time domain; wave propagation; bi-gyrotropic; chiral; bi-isotropic; Forerunner; precursor; Green dyadics; Electronics and Electrical technology; Elektronik och elektroteknik;

    Sammanfattning : This thesis treats the problem of transient electromagnetic pulse propagation in temporally dispersive media. The analysis is performed using time-domain techniques. In particular, the dispersive wave splitting which decouples the Maxwell equations both in vacuum and inside the medium is utilized. LÄS MER

  7. 5. Wireless Communication with Medical Implants: Antennas and Propagation

    Författare :Anders J Johansson; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; medical implant communication; electromagnetic propagation; biomedical telemetry; antennas in matter; MICS; Electronics; Elektronik;

    Sammanfattning : With the increased sophistication of medical implants, there is a growing need for flexible high-speed communication with the implant from outside the body. Today the communication is done by an inductive link between the implant and an external coil at a low carrier frequency. LÄS MER