2010/05/02 by Shabnam Ghadarghadr, Ghadarghadr, Shabnam, Hossein Mosallaei +1
Engineering · Mathematics · Physics and Astronomy · #Advanced Antenna and Metasurface Technologies #Antenna Design and Analysis #Computational Physics (physics.comp-ph) #Electromagnetic Theory #FOS: Physical sciences #Mathematical Physics (math-ph) #Microwave Engineering and Waveguides #math-ph #math.MP #physics.comp-ph
paper · pdf · doi:10.48550/arxiv.1005.0124
17 pages, 15 figures (total of 25 plots)
arxiv created 2010/05/02 · openalex publication_date 2010/05/02 · arxiv updated 2010/05/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The main goal of this work is to theoretically investigate the behavior of an\nelectrically small antenna enclosed in a concentric sphere. The Greens function\nanalysis is applied to characterize the input impedance of a concentric\nresonator excited by a dipole located at its center. The method of moments\n(MoM) with Galrekin's procedure is used to determine the current distribution\nover the source excitation and hence the input impedance. The behavior of\nquality factor (Q) and bandwidths of the antenna is studied with the use of\ninput impedance as a function of frequency. We illustrate that by embedding a\ndipole antenna inside a core-shell structure, with magnetic shell and\ndielectric core, a Q as low as the Chu limit can be approached. The obtained\nobservations demonstrate how a resonator composed of magnetic shells can\nprovide electrically small antennas with high bandwidths performance.\n