Hand loading usually degrades the performance of handset antennas. With the aim of providing a solution robust to the human presence, this paper discloses a distributed antenna system fed in-phase capable of mitigating undesirable hand loading effects while providing enhanced performance. The solution consists of a passive array of two resonant coplanar monopole antennas inspired in the Hilbert geometry. Input impedances of both monopoles are combined into a single input-output port through two transmission lines featuring equal phases. This combination allows not only improving the performance of the radiating system with respect to that attained by a single monopole antenna, but also providing a symmetric solution immune to the finger location. The solution is compared with a single monopole and a distributed antenna system fed out-of-phase. Simulated and measured results demonstrate that the proposed design is capable of providing operation in the communication standards GSM850/GSM900 as well as in the UHF part of the LTE-Advanced while maintaining the same electromagnetic performance with certain independence of the finger location.Index Terms-Broadband matching networks, electrical models, hand loading, handset antennas, low-profile, multi-band.

Wireless devices such as smart meters, trackers, and sensors need connections at multiple frequency bands with low power consumption, thus requiring multiband and efficient antenna systems. At the same time, antennas should be small to easily fit in the scarce space existing in wireless devices. Small, multiband, and efficient operation is addressed here with non-resonant antenna elements, featuring volumes less than 90 mm3 for operating at 698–960 MHz as well as some bands in a higher frequency range of 1710–2690 MHz. These antenna elements are called antenna boosters, since they excite currents on the ground plane of the wireless device and do not rely on shaping complex geometric shapes to obtain multiband behavior, but rather the design of a multiband matching network. This design approach results in a simpler, easier, and faster method than creating a new antenna for every device. Since multiband operation is achieved through a matching network, frequency bands can be configured and optimized with a reconfigurable matching network. Two kinds of reconfigurable multiband architectures with antenna boosters are presented. The first one includes a digitally tunable capacitor, and the second one includes radiofrequency switches. The results show that antenna boosters with reconfigurable architectures feature multiband behavior with very small sizes, compared with other prior-art techniques.

El aparentemente tranquilo sector turístico está siendo testigo de una revolución silenciosa que obligará a Pymes y destinos turísticos a adaptarse a una nueva realidad si quieren sobrevivir y aprovechar las nuevas oportunidades que están surgiendo. Los mercados emisores clásicos siguen creciendo, pero a una tasa muy inferior a la de los nuevos mercados emergentes como China, Brasil o Rusia, lo cual tendrá efectos difíciles de prever sobre los flujos internacionales de turistas y las motivaciones de viaje. Al mismo tiempo Internet, que ya representa una cuota de mercado muy importante en USA y Europa, va a convertirse también en un canal fundamental en los nuevos mercados en desarrollo. Los agentes han cambiado, pero la intensidad competitiva del mercado no se ha reducido, las principales agencias de viajes online compiten de forma intensiva por los usuarios que tratan de reservar un viaje a través de Internet, al mismo tiempo que ha aparecido un nuevo tipo de consumidor mucho más acostumbrado a viajar, diverso y complejo, todo ello obligará a desplegar nuevas estrategias de marketing. Pero sin duda, el cambio más importante se encuentra en la aparición de nuevos actores y modelos de negocio disruptivos gracias a la tecnología y a la disponibilidad de ingentes cantidades de información, que permiten proporcionar información local, contextualizada y en tiempo real al turista, al mismo tiempo que dirigir las acciones de marketing de forma mucho más precisa. Palabras Claves turismo, mercados internacionales, agencias de viajes online, información, Internet, revolución, modelos de negocio

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