Advancements in medical science and technology, medicine and public health coupled with increased consciousness about nutrition and environmental and personal hygiene have paved the way for the dramatic increase in life expectancy globally in the past several decades. However, increased life expectancy has given rise to an increasing aging population, thus jeopardizing the socio-economic structure of many countries in terms of costs associated with elderly healthcare and wellbeing. In order to cope with the growing need for elderly healthcare services, it is essential to develop affordable, unobtrusive and easy-to-use healthcare solutions. Smart homes, which incorporate environmental and wearable medical sensors, actuators, and modern communication and information technologies, can enable continuous and remote monitoring of elderly health and wellbeing at a low cost. Smart homes may allow the elderly to stay in their comfortable home environments instead of expensive and limited healthcare facilities. Healthcare personnel can also keep track of the overall health condition of the elderly in real-time and provide feedback and support from distant facilities. In this paper, we have presented a comprehensive review on the state-of-the-art research and development in smart home based remote healthcare technologies.
Utilising an array that is constructed by combining short-ended stubs and microstrip lines, a planar-choke structure is presented. By locating the proposed chock structure on the bottom of the substrate-integrated waveguide slot array antenna, undesired spillover current and edge diffractions are removed. Measurement result show that in the operational bandwidth the backward radiation is reduced by more than 20 dB and the side-lobe level is improved by 5 dB without degrading of the antenna's electrical performance.Introduction: Owing to the attractive features of slot array antennas such as high gain, high efficiency and mechanical strength, they are widely used in radar and communication systems [1]. The longitudinal shunt slot array is the most common structure in many applications owing to its low cross-polarised levels [2]. With this antenna, the defined gain and the side-lobe level (SLL) can be achieved using Elliott's design method [3,4]. However, this method is not considered for the back-lobe radiation level. Substrate-integrated waveguide (SIW) technology has the advantages of low profile, small size, ease of fabrication and low cost [5]. To improve the front-to-back ratio (FTBR), previous studies have reported methods such as placing a reflector or an absorber in the antenna downside [6,7], adding metal sidewalls [8] and using an electromagnetic bandgap [9]. The main disadvantages of these methods are increasing the SLL and the size of the antenna.In this Letter, a planar-choke structure is proposed for improving the FTBR and the SLL of the SIW-fed slot array antenna. The proposed structure creates a very high impedance surface at the ground plane of the conventional antenna that eliminates the edge diffractions related to the undesired surface current.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.