Modern Ultra-Wide Band (UWB) regulations have recently been adopted worldwide allowing for unlicensed operation within 3.1 and 10.6 GHz, using an appropriate wideband signal format with a low Effective Isotropic Radiated Power (EIRP) level. UWB characteristics are suitable to transmit data using pulses instead of continuous-waves such as in narrowband radio links. It has the potential to be the right technology for high data-rate, low-power and short-to-medium range communication systems.We will focus on Impulse Radio-UWB (IR-UWB) systems and show their suitability for many different applications, including sensor networks, ad-hoc networks, cognitive radio, home networking, etc. We will also discuss the difficulties and challenges of designing IR-UWB systems. We present a tutorial overview of UWB regulations and usable signals.We present the existing standards and recommendations, and we review recently published results, highlighting trends in UWB transceiver power consumption and the impact of CMOS scaling on performance.

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Thin films of bioactive glass-ceramics have been deposited on titanium and silicon substrates by RF magnetron sputtering. The crystalline phases and the microstructure of the films have been characterized using XRD and SEM analysis; the main phases present were calcium-magnesium phosphates, enstatite and forsterite. The adhesion of the films on titanium has been examined by pull-off testing; the adhesion strength for as-deposited films was around 40 MPa, but after crystallization the strength dropped to about half this value due to the presence of cracks. Samples kept in simulated body fluid showed an apatite-like layer, suggesting that the films are bioactive.