Engineering topics
Publications and source records attributed to Williams, Jeffery Thomas.
This powerpoint presents a sparse transmitarray design for 6G technology. The proposed approach leverages aperiodic arrays with large inter-element spacings, offering grating lobe-free operation, enhanced gain, and narrow beamwidths. The transmitarray topology, designed for sub-THz and THz frequencies, simplifies feed-network complexity, and minimizes losses. Numerical analysis and full wave simulation results show this approach is feasible.
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We summarize the narrow slot algorithms, including the thick electrically small depth case, conductive gaskets, the deep general depth case, multiple fasteners along the length, and finally varying slot width.
In this article, we examine the coupling into an electrically short azimuthal slot on a cylindrical cavity operating at fundamental cavity modal frequencies. We first develop a matched bound formulation through which we can gather information for maximum achievable levels of interior cavity fields. Actual field levels are below this matched bound; therefore, we also develop an unmatched formulation for frequencies below the slot resonance to achieve a better insight on the physics of this coupling. Good agreement is observed between the unmatched formulation, full-wave simulations, and experimental data, providing a validation of our analytical models. We then extend the unmatched formulation to treat an array of slots, found again in good agreement with full-wave simulations. These analytical models can be used to investigate ways to mitigate electromagnetic interference and electromagnetic compatibility effects within cavities.
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This report explores the potential for reducing the fields and the quality factor within a system cavity by introducing microwave absorbing materials. Although the concept of introducing absorbing (lossy) materials within a cavity to drive the interior field levels down is well known, increasing the loading into a complex weapon cavity specifically for improved electromagnetic performance has not, in general, been considered, and this will be the subject of this work. We compare full-wave simulations to experimental results, demonstrating the applicability of the proposed method.
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