Journal ArticleDOI
On the performance properties of the Koch fractal and other bent wire monopoles
TLDR
In this article, the performance properties of the Koch fractal monopole are examined and compared with the performance of other bent wire geometry monopoles having the same total wire length and overall height, and it is shown that the fractal limit in lowering of resonant frequency is related to the limit in the increase in the antenna's effective volume.Abstract:
Koch fractal monopole antennas are known to exhibit lower resonant frequencies than Euclidean monopoles of the same height. It has been concluded that there exists a unique relationship between the antenna's fractal geometry and its electromagnetic behavior. Here, the performance properties of the Koch fractal monopole are examined and compared with the performance properties of other bent wire geometry monopoles having the same total wire length and overall height. It is demonstrated that monopoles with less complex shapes exhibit lower resonant frequencies because they are more effective at increasing the electrical volume of the antenna. When these antennas are made to be resonant at the same frequency, they exhibit virtually identical performance properties independent of differences in their geometric shape and total wire length. It is also demonstrated that the effective height of these monopoles converge to that of an electrically small Euclidean monopole near the small antenna limit and they exhibit virtually identical radiation resistance properties at low frequencies. Finally, it is shown that the fractal limit in lowering of resonant frequency is related to the limit in the increase in the antenna's effective volume.read more
Citations
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Journal ArticleDOI
The radiation properties of electrically small folded spherical helix antennas
TL;DR: The radiation properties of several electrically small, folded spherical helix antennas are presented in this paper, where the principle design objectives are to achieve self resonance, a low quality factor (Q), and a practical radiation resistance for small values of ka.
Journal ArticleDOI
Experimental Validation of Performance Limits and Design Guidelines for Small Antennas
Daniel F. Sievenpiper,David Carlos Dawson,Minu M. Jacob,Tumay Kanar,Sanghoon Kim,Jiang Long,Ryan Quarfoth +6 more
TL;DR: In this article, the theoretical performance limit for small antenna performance has been validated by all available experimental evidence and the theoretical predictions for the performance due to design factors such as permittivity, aspect ratio, and the internal structure of the antenna are also supported by the experimental evidence.
Journal ArticleDOI
Hybrid Fractal Shape Planar Monopole Antenna Covering Multiband Wireless Communications With MIMO Implementation for Handheld Mobile Devices
TL;DR: In this article, a hybrid fractal shape planar monopole antenna covering multiple wireless communication bands is presented for multiple-input-multiple-output (MIMO) implementation for handheld mobile devices.
Journal ArticleDOI
Low Q electrically small linear and elliptical polarized spherical dipole antennas
TL;DR: In this paper, a self-resonant, electrically small electric dipole antenna is presented that exhibits an impedance near 50 Ohms, an efficiency in excess of 95% and a quality factor that is within 1.5 times the fundamental lower bound at a value of less than 0.27.
Journal ArticleDOI
Electrically small supergain end-fire arrays
TL;DR: In this paper, the authors show how the difficulties of narrow tolerances, large mismatches, low radiation efficiencies, and reduced scattering of electrically small parasitic elements can be overcome by using small resonant antennas as the elements in both separately driven and singly driven (parasitic) two-element, electrically-small supergain end-fire arrays.
References
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Journal ArticleDOI
Physical Limitations of Omni-Directional Antennas
TL;DR: In this paper, the physical limitations of omni-directional antennas are considered and the potentiality of a broad band width of an antenna with the maximum dimension of 2a has been shown.
Journal ArticleDOI
Fundamental Limitations of Small Antennas
TL;DR: In this paper, a simple formula for the more fundamental properties of small antennas and their behavior in a simple circuit is given for 1-Mc operation in typical circuits, which indicates a loss of about 35 db for the I.R.E. standard capacitive antenna, 43 db for a large loop occupying a volume of 1 meter square by 0.5 meter axial length, and 64 db for an antenna loop of 1/5 these dimensions.
Journal ArticleDOI
Fundamental limitations in antennas
TL;DR: In this article, four fundamental limitations in antennas have been identified in the areas of: electrically small antennas, super-directive antenna, superresolution antennas, and high-pin antennas.
Journal ArticleDOI
The Koch monopole: a small fractal antenna
TL;DR: In this article, the behavior of the small fractal Koch monopole is numerically and experimentally analyzed, and it is shown that as the number of iterations on the small Koch monopoles are increased, the Q of the antenna approaches the fundamental limit for small antennas.
Journal Article
Small antennas
TL;DR: In this article, the authors reviewed the radiation power factor of a small antenna in terms of its effective volume, which is proportional to the effective volume of the antenna's antenna array.