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Authors
Advisor(s)
Abstract(s)
Os radares de Micro-Doppler têm sido amplamente utilizados para a aquisição remota
de sinais vitais. Este tipo de radar é tipicamente denominado de Bio-Radar. A qualidade do sinal vital obtido está diretamente relacionada com a potência recebida, que pode ser inferida através da equação do radar. No entanto, existem outros aspetos que influenciam a potência recebida, especialmente quando o alvo de interesse está localizado próximo das antenas. Para melhor compreender a configuração ótima do radar,
é necessário estudar a propagação do canal de rádio, cujo estudo tem sido escasso na literatura.
Neste trabalho, foram realizadas simulações e experiências para caracterizar a variação da potência do sinal recebido, bem como a Secção Eficaz de Dispersão (RCS), de acordo com a distância em relação ao Bio-Radar. O trabalho realizado, que envolveu a realização de simulações e medições práticas em formas geométricas conhecidas, não só ajudou a validar o software utilizado nas simulações, mas também o método prático de medição da potência recebida realizado na câmara anecoica. Posteriormente, foi realizada uma análise em seres humanos, revelando que vários fatores poderiam influenciar os resultados obtidos, como a postura dos sujeitos e os seus padrões de respiração. No geral, para obter uma boa medida do sinal respiratório, distâncias mais curtas, até 1 metro, tendem a ser as mais adequadas.
Micro-Doppler radars have been widely used for the remote vital signs acquisition. These type of radars are commonly known as Bio-Radar. The obtained vital signal quality is directly related with the received power, which can be inferred by using the radar equation. Nevertheless, there are other aspects that influence the received power, especially when the the target of interest is located near the antennas. To better understand the optimal radar configuration, it is necessary to study the propagation of the radio channel, whose study has been lacking in the literature. In this work, simulations and experiments were performed to characterise the received signal power variation as well as the Radar Cross Section (RCS), according to the distancie in relation to the Bio-Radar. The work performed, which involved conducting simulations and practical measurements on well-known shapes, has not only helped validate the software used in the simulations but also the practical measuring method of received power conducted in the anechoic chamber. Subsequently, an analysis was performed on human subjects, revealing that various factors could influence the ob tained results, such as the posture of the subjects and their breathing patterns. Overall, for improved respiratory signal measurement, shorter distances, up to 1 meter, tend to be the most adequate.
Micro-Doppler radars have been widely used for the remote vital signs acquisition. These type of radars are commonly known as Bio-Radar. The obtained vital signal quality is directly related with the received power, which can be inferred by using the radar equation. Nevertheless, there are other aspects that influence the received power, especially when the the target of interest is located near the antennas. To better understand the optimal radar configuration, it is necessary to study the propagation of the radio channel, whose study has been lacking in the literature. In this work, simulations and experiments were performed to characterise the received signal power variation as well as the Radar Cross Section (RCS), according to the distancie in relation to the Bio-Radar. The work performed, which involved conducting simulations and practical measurements on well-known shapes, has not only helped validate the software used in the simulations but also the practical measuring method of received power conducted in the anechoic chamber. Subsequently, an analysis was performed on human subjects, revealing that various factors could influence the ob tained results, such as the posture of the subjects and their breathing patterns. Overall, for improved respiratory signal measurement, shorter distances, up to 1 meter, tend to be the most adequate.
Description
Dissertação para obtenção do Grau de Mestre em Engenharia Eletrónica e de Telecomunicações
Keywords
Bio-Radar Vital signs Near-field radar Radar Cross Section Sinais Vitais Radar em região de campo próximo Secção Eficaz de Dispersão
Citation
CRUZ, Beatriz Bento da - Study of the bio-radar radio channel. Lisboa: Instituto Superior de Engenharia de Lisboa, 2023. Dissertação de mestrado.
Publisher
Instituto Superior de Engenharia de Lisboa