Antenna for indoor guidance

Abstract

Com os avan cos tecnol ogicos que se têm registado nos ultimos anos torna-se, cada vez mais, necess ario desenvolver solu cões que permitam facilitar o dia-a-dia das pessoas que sofrem de alguma impossibilidade f sica. E de facto crucial come car a aplicar a tecnologia no desenvolvimento de sistemas que permita a essas pessoas tornarem-se independentes e capazes de responder a todas as tarefas di arias. Assim, inspirado pelo Instrument Landing System (ILS), que e um sistema que permite aos pilotos aterrarem os aviões em seguran ca quando as condi cões metereol ogicas e visuais não são as mais favor aveis, pretende-se desenvolver um mecanismo que permita aos invisuais identi carem a aproxima cão de uma porta, e consequemente ajud a-los a entrar ou sair da divisão. De um modo geral, este trabalho foca-se no desenvolvimento de uma antena que permita fazer a identificação da porta. Pretende-se que a antena apresente um diagrama de radia ção com a forma de uma bolacha, pois a detecçãco do m aximo ir a levar a entrada ou sa da correcta da porta. Para atingir este objectivo, a antena a ser desenvolvida e um agregado linear e uniforme de dipolos, cujo o diagrama de radia c~ao cumpre as especi ca cões pretendidas. Outro aspecto importante acerca do agregado de dipolos diz respeito a sua constru cão, pretende-se que a antena a desenvolver seja impressa. Esta op cão prende-se com a sua rela cão simplicidade e baixo custo com e ciência e desempenho.

With all the technological developments that have happened during the past few years, it has become necessary to come up with systems that are capable of improving everyday tasks of people who have physical disabilities. Actually, it is important to improve the living conditions of these people by providing them mechanisms that would make them stop relying on the others. Bearing this in mind, the idea for this dissertation was inspired by the ILS, which is a landing system that allows pilots to land with safety in poor visibility and weather conditions. It is aimed to design an antenna for a system that helps the visually impaired or the blind to guide themselves indoor. In fact, it is intended to develop a system that helps them to identify a door, and at the same time guide them to enter or exit the room correctly. In general, this work is focussed in the design of a suitable antenna for door identi cation. The main speci cation that the antenna has to meet is having an extremely narrow radiation pattern. The reason behind this speci cation is due to the way that the receiver would know when to tell the user that a door entrance is approaching, in other words, the identi cation of a door is made through maximum search of the radiation pattern. When this maximum value is found, the person knows that he or she is correctly positioned to enter or exit the room. The antenna would be a linear array of uniform amplitudes and spacing of dipoles with a radiation pattern similar to a cookie. Another aspect concerning the antenna is what materials it would be made of. Considering the relation between simplicity and low-cost with e ciency and performance, a printed antenna would be the ideal solution for the project's system.