169 research outputs found
Perturbation of the sierpinski antenna to allocate the operating bands
A scheme for modifying the spacing between the bands of the Sierpinski antenna is introduced. Experimental results of two novel designs of fractal antennas suggest that the fractal structure can be perturbed to enable the log-period to be changed while still maintaining the multiband behaviour of the antenna.Peer ReviewedPostprint (published version
Miniature Wideband stacked microstrip patch antenna based on the sierpinski fractal geometry
The main interest in the design of a miniature microstrip patch antenna (MPA) is its small size in conjunction with the well-known advantages of a MPA (cost, profile, weight). However there is a big constraint on the bandwidth limitation either in a miniature antenna or in a MPA. The proposed solution to overcome such problem is to couple a miniature parasitic resonator to the miniature active patch forming a wideband small stacked microstrip patch antenna.Peer ReviewedPostprint (published version
Small but long koch fractal monopole
A small but long wire fractal antenna based on the Koch curve is presented. Experimental and numerical results show that the antenna improves the features of a common linear monopole. The radiation resistance is increased and the Q is reduced at each fractal iteration, approaching the fundamental limit on small antennas.Peer ReviewedPostprint (published version
The Koch monopole: a small fractal antenna
Fractal objects have some unique geometrical properties. One of them is the possibility to enclose in a finite area an infinitely long curve. The resulting curve is highly convoluted being nowhere differentiable. One such curve is the Koch curve. In this paper, the behavior the Koch monopole is numerically and experimentally analyzed. The results show that as the number of iterations on the small fractal Koch monopole are increased, the Q of the antenna approaches the fundamental limit for small antennas.Peer Reviewe
Active zone self-similarity of fractal sierpinski antenna verified using infra-red thermograms
The surface current distribution of a Sierpinski fractal antenna shows a self-similar behaviour determined by the self-similar properties of its geometry. The application of infra-red thermography to electromagnetic near field detection allows the experimental verification of the active region scaling of a fractal antenna operating at different bands.Peer ReviewedPostprint (published version
How much can be reduced the internal FM antenna of mobiles phones?
The paper introduces both a new internal FM antenna for mobile phones based on the fractal Hilbert curve, and a new evaluation criterion for quantifying the quality of the signal received by the FM antenna of mobile phones. The main attribute of the new internal FM antenna is its reduced size; which is only 30⋆10⋆1 mm3. The measurements demonstrate that the power received by the internal FM antenna is 20 dB lower than the power received by the external wire antenna under the same measurement conditions. Despite the reduction of the power level, the evaluation criterion reveals that, owing to the threshold effect in FM receivers, the signal quality indicator is similar for both antennas. Additionally, the value of the signal quality indicator achieved by both antennas guarantees to listen to the FM radio channels clearly without noise nuisance and without interferences.Peer ReviewedPostprint (published version
Premio EITP'98 para las Antenas Fractales
Peer Reviewe
Análisis y diseño de monopolos acoplados para dispositivos móviles multibanda
A novel low profile planar antenna is proposed. The
antenna presented is a coupled monopole antenna, comprising
at least a driven element coupled with one or more parasitic
elements. The design proposed is suitable to be used into a
handheld device. The dimensions of the antenna are 33x15x1
mm
3
. In order to facilitate the integration of other components,
such cameras or speakers, a ground plane area at the right side
of the antenna is provided. The study carried out reveals the
relevance of the arms location over the performance of the
antenna. The theoretic base is reinforced by a network model
and a parametrical study. The coupling between elements
controls the behaviour of the antenna. In this sense, a weak
coupling between the driven element and at least one parasitic
element enhances the bandwidth, whereas a multiband
behaviour is achieved by a strong coupling. Finally, the PCB
(Printed Circuit Board) influence has also been analyzedPeer ReviewedPostprint (published version
Antena microstrip dual en frecuencia basada en el triángulo fractal de Sierpinski
A dual-frequency antenna based on the
Sierpinski fractal with two parasitic patches to enhance the
impedance bandwidth is presented. An electrical circuit
model formed by RLC resonators is proposed to learn
about the antenna physical behavior and to achieve the
dual band operation minimizing a trial-and-error
numerical/ measurement proofs. The antenna has been
designed using a MoM commercial code and has been
experimentally tested, obtaining two bands with a
bandwidth around 7%(SWR<2) and similar radiation
pattern and gain.Peer ReviewedPostprint (published version
On the behavior of the Sierpinski multiband fractal antenna
The multiband behavior of the fractal Sierpinski antenna is described. Due to its mainly triangular shape, the antenna is compared to the well-known single-band bow-tie antenna. Both experimental and numerical results show that the self-similarity properties of the fractal shape are translated into its electromagnetic behavior. A deeper physical insight on such a behavior is achieved by means of the computed current densities over the antenna surface, which also display some similarity properties through the bands.Peer Reviewe
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