Circularly Arced Koch Fractal Multiband Multimode Monopole Antenna

Abstract

Abstract-Circularly arced Koch fractal curve (CAKC) is originally proposed. Then, a novel wire dipole is formed with K i -iterated CAKC. The dipole is experimentally studied for fractal electrical characteristics revealing. It manifests many unique properties, such as multiband resonance at odd times of half-wavelength. In particular, it unprecedentedly presents normal mode (0.5 · λ) and axial mode (1.5 · λ) simultaneously. Thus, K 2 CAKC wire is configured into folded monopole with circular disc ground for omni-directional and directive radiation. Five matched bands (|S 11 | ≤ −10 dB) are obtained within 1 GHz-10 GHz, of which f 1 = 1.31 GHz, f 2 = 3.14 GHz, f 3 = 3.63 GHz, f 4 = 4.65 GHz, and f 5 = 7.71 GHz. Compared with straight wire monopole (0.25 · λ), this fractal monopole shows 31% height reduction. It has dipole-like patterns at f 1 and f 2 , endfire patterns at f 3 and f 4 with high gain (10 dBi), and off-endfire patterns at f 5 . Moreover, the fractal antenna possesses compactness, lightweight, simplicity, and low cost. So, it is an attractive candidate for multiband and multifunction antennas, such as satellite antennas, of which omnidirectional normal mode and directive axial mode are needed for beaconing and communication respectively.

Ultra‐wideband high‐gain dipole antenna evolved from hexagonal Sierpinski grid fractal gasket

“…Therefore, an optimal fractal should be conceived before that we develop a novel fractal antenna. Thus far, commonly used fractals for antennas are monopole/dipole antennas [12,17,18], loop antennas [19], helix antennas [19], dielectric resonator antennas [20] and so on, including Koch/Koch-like series [21], Minkowski series [22,23], Peano series [24], Sierpinski series [10,13,[24][25][26][27], Hilbert series [28], and so on. Based on Sierpinski fractal gasket [27,29,30], we develop a new variant -modified K 2 Y-loaded hexagonal Sierpinski grid carpet (MHSC).…”

A Novel Low Cost Fractal Antenna Structure for ISM and WiMAX Applications

“…Actually, the developing of multiband antennas have been improved through the use of the fractal concept [13][14][15]. Fractal geometry [16] plays an important role in these requirements. The term fractal geometry was first created by Mandelbrot [17][18][19] to describe a family of complex forms that have self-similarity or self-affinity in their geometrical structure.…”

A New Method of Driving Wire Dipole Antennas to Multiband Operation via Non-Uniform Ebg Lattices for Employment to Wireless Communication Applications

“…Several techniques to this aim obtained are found in the literature, especially for printed dipoles. To drive this antenna type at multi-frequency operation is easier than to do it in the case of a wire dipole, as the designer has the potential to suitably configure printed element's shape for example fractaly, or to incorporate into them metamaterial elements [20][21][22][23][24][25][26][27][28] thus obtaining simultaneously compact antennas with low profile. In the work at hand in accordance to the scope of utilizing wire dipoles performing at more than one frequency bands, the problem's solution was given by employing a planar nonuniform EBG in close proximity to the dipoles.…”