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A key part of every space science mission, in the system-level approach, is the detailed study and modeling of the emissions from transmission lines. Harnesses usually emit electromagnetic fields due to the currents (of common and/or differential modes) that flow on their shields. These fields can be identified via conducted emissions measurements. Relying on the operating frequency, any cable can be considered as a dipole or a traveling-wave antenna. Limited work can be found in the literature regarding modeling methodologies for cable topologies, especially in the low frequency (ELF, SLF, VLF, LF) domain. This work intends to provide perceptions for the precise estimation of harness radiated emissions, consider a mission-specific measurement point (where the sensors are placed), and follow ESA's recent science mission studies for electromagnetic cleanliness applications. For the low frequencies considered herein, any linear cable path is considered as a point source (infinitesimal dipole) and we evaluate its effect on the calculated electric field extremely close to the source. For such distances, it is shown that the dipole representation is not accurate. To remedy this phenomenon, this article proposes a methodology, which can be easily expanded to complex cable geometry cases. [ABSTRACT FROM AUTHOR]

The classical Sommerfeld problem of a vertical electric dipole radiating over an imperfectly conducting half-space is revisited. Two variants of the modified saddle-point integration method are employed to derive new, closed-form, second-order approximations of the far-zone electromagnetic fields. The new formulas are applied to compute radiation patterns and surface fields for sample problems including both ordinary and plasmonic media, and their accuracy is assessed by comparison with the results of rigorous numerical evaluation of the Sommerfeld integrals. [ABSTRACT FROM PUBLISHER]

The surface electromagnetic fields radiated by a vertical electric dipole over a lossy conducting half-space are investigated. A simple derivation is presented of the second-order asymptotic groundwave expression, using a modified saddle-point method based on integration around vertical branch cuts. The method takes into account the influence of the Sommerfeld pole, which in the plasmonic case contributes a surface plasmon polariton. The proposed groundwave formulation is shown to be superior to the state-of-the-art Norton–Bannister theory for noble metals at optical wavelengths. [ABSTRACT FROM PUBLISHER]

The electromagnetic interference generated by a switched-mode power supply on a victim circuit is analysed representing their electromagnetic field coupling by two-port networks. The essential electromagnetic interference sources of the switched-mode power supplies are individuated and their mutual impedances with the victim circuit are calculated by the induced EMF method. The two-port representation of the field coupling allows the noise voltage on a victim circuit to be predicted. As a victim circuit a circular loop representing a magnetic field probe used in near field measurements is considered. The approach is applied to a flyback converter and validated through experimental measurements. [ABSTRACT FROM AUTHOR]