Development of miniaturized antennas and adaptive tuning solutions for body sensor network applications

Wireless Sensor Networks (WSNs) are currently having a revolutionary impact in rapidly emerging wearable applications such as health and fitness monitoring amongst many others. These types of Body Sensor Network (BSN) applications require highly integrated wireless sensor devices for use in a wearable configuration, to monitor various physiological parameters of the user. These new requirements are currently posing significant design challenges from an antenna perspective. This work addresses several design challenges relating to antenna design for these types of applications. In this thesis, a review of current antenna solutions for WSN applications is first presented, investigating both commercial and academic solutions. Key design challenges are then identified relating to antenna size and performance. A detailed investigation of the effects of the human body on antenna impedance characteristics is then presented. A first-generation antenna tuning system is then developed. This system enables the antenna impedance to be tuned adaptively in the presence of the human body. Three new antenna designs are also presented. A compact, low-cost 433 MHz antenna design is first reported and the effects of the human body on the impedance of the antenna are investigated. A tunable version of this antenna is then developed, using a higher performance, second-generation tuner that is integrated within the antenna element itself, enabling autonomous tuning in the presence of the human body. Finally, a compact sized, dual-band antenna is reported that covers both the 433 MHz and 2.45 GHz bands to provide improved quality of service (QoS) in WSN applications. To date, state-of-the-art WSN devices are relatively simple in design with limited antenna options available, especially for the lower UHF bands. In addition, current devices have no capability to deal with changing antenna environments such as in wearable BSN applications. This thesis presents several contributions that advance the state-of-the-art in this area, relating to the design of miniaturized WSN antennas and the development of antenna tuning solutions for BSN applications.

Territorial development, planning reform and urban governance: the case of Ireland's second-tier cities

The increased emphasis within Europe on the role of second-tier cities has implications for the ways in which these urban centres are considered within national spatial planning strategies. In centralised, monocentric states like Ireland, there has been a general ambivalence towards urban policy for cities outside the capital city, and historically this has prevented the development of a strong, diversified urban hierarchy undermining prospects for balanced regional development. This paper examines the extent to which a new found emphasis on Ireland’s second-tier cities which emerged in the ‘Gateways’ policy of the National Spatial Strategy (NSS, 2002) was matched by subsequent political and administrative commitment to facilitate the development of these urban centres. Following a discussion of the position of second-tier cities in an international context and a brief overview of recent demographic and economic trends, the paper assesses the relative performance of Ireland’s second-tier cities in influencing development trends, highlighting a comprehensive failure to deliver compact urban growth. In this context, the paper then discusses the implications of current development plans for the second-tier cities and proposals for Irish local government reform for securing compact urban development.