Browsing by Issue Date, starting with "2015-10-26"
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- Circularly polarized microstrip antenna array for the Ka-bandPublication . Varum, Tiago; Matos, Joao; Duarte, Vanessa; Pinho, PedroThe growing needs of higher transmission rates lead to the use of the Ka frequency bands and multi-beam technology, in the satellite communications, allowing more coverage. This fact leads to the need for the use of directive antennas and beamforming techniques to achieve a precise control of radiation pattern. This paper presents the design of a circularly polarized microstrip antenna array, at 29 GHz, suitable to satellite communications. The array will be a module part to develop an ample antenna array suitable to fulfill the satellite requirements, and feed with an electronic beamforming network.
- Parasitic stacked slot patch antenna for DTT energy harvestingPublication . Moura, Tiago; Brás, Luís; Pinho, Pedro; Carvalho, Nuno; Gonçalves, RicardoIn this paper a rectangular patch antenna with two slots, integrated with a stacked parasitic antenna, is presented. These techniques allow a bandwidth (BW) and gain enhancement, two of the major limitations of traditional patch antennas. The antenna is designed to operate at 754 MHz for energy harvesting applications, from the Portuguese Digital Terrestrial Television (DTT) signal. The measured antenna BW is 22.5 MHz, representing an enhancement of around 17 MHz in respect to the simulated BW of the corresponding single patch configuration.
- Transparent antenna applied for RF harvesting applicationsPublication . Brás, Luís; Pinho, Pedro; Carvalho, NunoWith the tremendous growth and relevance of Internet of Things (IoT) is last years it became a demand to identify, communicate and transfer energy to all objects. These technologies are often desired to be hidden (or transparent) to the human eyes, not only by its aesthetic reasons but also by its reusability of the space which is often crucial. This reasons led to a significant grow in research of transparent conductors and antennas. Transparent antennas are characterized by a certain level of optical transparency and are potentially suitable for automotive industry mainly for vehicular communications; integration with solar panels of small satellites and lately for wireless power transmission.
- Fisioterapia em crianças com necessidades especiais: relatório de estágio em reabilitação neurológicaPublication . Graça, Noémia Marques; Bernardo, Ana CarolinaEste relatório de estágio diz respeito ao trabalho de estágio inserido do Mestrado em Fisioterapia da Escola Superior de Tecnologia da Saúde de Lisboa. No relatório serão apresentadas as atividades com especial incidência na população pediátrica que decorreu entre os meses de Janeiro a Março 2014 e que envolveu: a observação de intervenções da fisioterapia em casos de paralisia cerebral, atrofia muscular espinhal, acidente vascular cerebral; o estudo de um caso clinico de uma criança com atrofia muscular espinhal tipo II; e a realização de fichas de desenvolvimento temático. Este estágio foi norteado por dois princípios, por um lado o desenvolvimento e a atualização da prática da fisioterapia nas patologias que constituíram o objetivo de estudo e de intervenção, e finalmente a abordagem na família com crianças com necessidades especiais. A doença crónica na infância apresenta uma prevalência bastante elevada e tem implicações para o desenvolvimento da criança e de seu convívio familiar. Cuidar da criança com doença crónica é uma experiência muito difícil para a família. Ela é o espaço social onde seus membros interagem, trocam informações, apoiam-se mutuamente, buscam e medeiam esforços para amenizar ou solucionar problemas. A família frequentemente apresenta pouca preparação psicológica para enfrentar a doença crónica na criança, o que leva a dificuldades da adaptação da criança e da própria família a esta nova situação. As mudanças que ocorrem nas vidas de ambos não são simplesmente alterações orgânicas ou físicas da criança, mais ultrapassam os aspetos mais físicos e implicam alterações emocionais e sociais em toda família sendo-lhes exigidos esforços continuados de adaptação. A fisioterapia tem um papel importante no desenvolvimento da criança, no aumento da sua funcionalidade e na qualidade de vida da criança e da família.
- Crossed sector automatic detection in 4G Radio Access NetworksPublication . Martins, A.; Vieira, Pedro; Franco, C.; Rodrigues, A.; Silva, N.The Long Term Evolution (LTE) is the latest step in the advancing series of mobile telecommunications systems, it is called the fourth Generation (4G). In order to boost performance and deal with the increasing complexity within the operating 3G/4G networks, the Self-Organizing Networks (SON) concept was introduced.
- Design and implementation of a 3D printed discone antenna for TV broadcasting systemPublication . Gonçalves, Ricardo; Pinho, Pedro; Carvalho, NunoDiscone antennas are wide bandwidth and omnidirectional radiation antennas that are widely used in VHF and UHF broadcasting systems. This paper presents the design and implementation of a discone antenna, for indoor use in a digital TV receiving/transmitting system, which was developed using 3D printing technology, allowing the development to be simple, quick and less expensive. The antenna presents a measured matched bandwidth, below - 10dB of return loss, between 380 MHz and 3 GHz. Simulation and measurements match, with the antenna presenting an omnidirectional radiation pattern within the considered TV band.
- Energy savings in 3G using dynamic spectrum access and base station sleep modesPublication . Cunha, T.; Rodrigues, A.; Vieira, Pedro; Martins, A.; Silva, N.; Varela, L.The energy consumption and energy efficiency of mobile telecommunication networks are crucial factors for the sustainability of this industry. This paper targets the reduction of the energy consumption at a Base Station (BS) level through the adoption of sleep modes during the off-peak periods of the day and relying in the existence of co-located and overlaid frequency bands to provide the coverage and capacity backup for the switched-off cells. It relies on the Dynamic Spectrum Allocation (DSA) method to opportunely relocate users during the low-load periods while maintaining the service quality of service (QoS). For the input data, real traffic statistics were used. Using this strategy and the proposed algorithm it was possible to achieve savings of about 43% per-site. The results were furthered to the study of a Portuguese mobile operator case and it was concluded that savings of more than 1.25 million euros were easily achieved.
- An enhanced proposal in neighbor list planning for LTE SON radio access networksPublication . Duarte, D.; Martins, A.; Vieira, Pedro; Rodrigues, A.; Silva, N.Nowadays, a coexistence of 2nd Generation (2G), 3rd Generation (3G) and 4th Generation (4G) networks is being witnessed. Due to this situation, it became evident the need for Self-Organizing Networks (SON), which aims to automate most of the associated radio planning and optimization tasks. Within SON, this paper presents the latest work around an algorithm that optimizes the Neighbor Cell List (NCL) for Long Term Evolution (LTE) evolved NodeBs (eNBs). The algorithm is based on intra-site distance, its antenna orientation (azimuth/elevation), radiation pattern and overlap areas between cells. The research initial steps were already published (Duarte, D.; Vieira, P.; Rodrigues, A.; Martins, A.; Oliveira, N.; Varela, L., “Neighbour List Optimization for Real LTE Radio Networks,” Wireless and Mobile, 2014 IEEE Asia Pacific Conference on, pp.183,187, 28-30 Aug. 2014).