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

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

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

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

Antenna microstrip triplebanda basada en el triangulo fractal de Sierpinski

Peer ReviewedPostprint (published version

Analysis of the specific absorption rate in handset antennas with slotted ground planes

The study of the interaction between human head and handset antennas should be taken into account since all the mobile phones have to guarantee a biological compatibility. This research analyzes several antennas with different slotted ground planes in terms of free space and also in terms of human head interaction. The main objective is to compare the measured bandwidth and efficiency in free space and the impact on measured SAR (Specific Absorption Rate) of such antennas as a function of the slot configuration and the antenna/slot location. Results show that slots may be useful to increase bandwidth and efficiency while keeping a similar SAR compared to the non-slotted ground plane. Changing the antenna and the slot location is a good way to achieve a significant SAR reduction.Peer ReviewedPostprint (published version

The Hilbert monopole revisited

A comparison between the resonant performance of the third iteration Hilbert monopole and a spiral shaped one of the same size and resonant frequency is presented. Quality factor, bandwidth, efficiency and radiation patterns are investigated. Although the Hilbert monopole total wire length is longer, it shows nearly the same radiation efficiency yet a lower quality factor. Hence the higher compression efficiency of the spiral shaped monopole does not provide any advantage in the antenna electromagnetic performance. Differences in radiation pattern are also observed. It is demonstrated that antenna resonance performance depends on its geometry, and not only on its size or wire length.Peer ReviewedPostprint (published version

Conformación del diagrama de radiación de un monopolo en L

The typical radiation pattern of an L-monopole antenna can be easily modified by changing the geometrical characteristics of the structure. To shape a specific radiation pattern through a basic structure becomes an interesting freedom degree in order to better adapt the behaviour of the antenna to the design specifications. Thus, to solve the question,an accurate analysis following the radiated field basic equations has been carried out. The theoretical study is validated through a simulation and experimental process. The results depict three main regions, delimited by geometrical boundaries, where the Lshaped wire antenna present three specific radiation pattern types, a monopole-type, a half isotropic type or even, a patchtype radiation pattern. Consequently, the method described herein demonstrates that simple modifications applied to the geometry of a basic structure, allow obtaining radiation properties associated to more complex structures.Peer ReviewedPostprint (published version

Agrupación submuestreada operando en modo fractón utilizando antenas microstrip inspiradas en el fractal de Sierpinski

A high-directivity microstrip array using mul- tilevel elements based on a fractal geometry is theoretically compared with one using a circular patches. Within the same electrical area, the same directivity can be obtained. However, the number of elements for the fractal-based ar- ray is 2.84 times less, reducing the complexity of the feeding network and overall arrayPeer ReviewedPostprint (published version

Propiedades de barrido de haz en agrupaciones de antenas utilizando elementos inspirados en el fractal de Sierpinski

A microstrip array using high-directivity Sierpinski fractal-inspired elements (under-sampled array) needs less elements than an array using elements operating at the fundamental mode (conventional array). Within the same electrical area, both the under-sampled and the conventional arrays present the same directivity. The advantage of the under-sampled array is that as a less number of elements is needed, it simplifies the feeding network facilitating the integration of other microwave components such as amplifiers, filters, and matching networks for example. Previous research has been carried out for under-sampled broadside array. In this paper, scanning properties of the under-sampled array are investigated.Peer ReviewedPostprint (published version