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bounds to the PM and AM noise of the second output harmonic, computed by Eqs. (1) and (2)-(6), are shown in Figure 2. The uncertainty on the output PM noise is of the order of 20.3 dB and is almost independent of fD. The expected output-to-input PM noise ratio of 6 dB is obtained for 3 = 0 within 50.005 dB, which indirectly confirms that 0 is the most likely value of 3.The output AM noise is very close to that of the source, with virtually zero uncertainty for f D 2 1 kHz. Only at very low frequency deviations and for 3 > 0 is some loss of numerical accuracy observed, due to the very high PM-to-AM noise ratio that makes the computation ill conditioned. It is thus clear that a valid noise analysis can indeed be performed by Eq. (6) on the basis of a simplified statistical description of the noisy source, consisting of PM and AM noise only. ABSTRACT In this article we present a modified least-squares boundary residual (LSBR) method for the rigorous analysis of microwave integrated circuits (MICs). The method is relatively convergent and a semianalytical relative convergence criterion is found to be very important in optimizing its convergence. Moreover, the problem of the poor conditioning of the least-squares matrices has been rigorouslv resolved.ABSTRACT A simple method for obtaining optical transmission spectra of AI, Ga,.,As epilayer by translucent A B wax is presented. Absorp-tion spectra are measured for x in the range of 0 < x < 0.8. For the Tlii Ti( energy bandgap, the aluminum concentrations, calculated from the experimental data with a formula derived by the ray-optics merhod, are in good agreement with those reported. 0 1992 John Wile! & Sons, Inc.

MotivationNowadays there is an almost unlimited number of monitoring applications, such as structural health, logistic, security, healthcare and agriculture, which are planning to be based on a large deployment of co-operative wireless microsystems, with sensing capabilities, moving closer to the effective realization of the paradigm of the Internet of Things. The main open challenge is the reliability of maintenance-free devices, with life-time duration, especially from the energy sustainability point of view. Such systems are required to power themselves, by harvesting energy from the ambient, thus eliminating battery needs. To minimize energy requirements, wake-up radios able to be activated by signals as low as -50 dBm are already available [1]. RF/microwave energy sources are foreseen as one of the best candidates to comply with energy autonomy, either because they are widely distributed in humanized environments or because they can be efficiently provided on demand. These two different ways of providing RF energy can be referred to as RF energy harvesting (EH) and wireless power transmission (WPT), respectively. In both cases a delicate design of the RF power transfer link, consisting of the nonlinear sub-systems and the radiating elements, is required, providing that their characteristics are carefully optimized depending on the particular contest and scenario. Intensive industrial and academic activities has been devoted to this field: several and concurrent techniques and circuit solutions have been proposed and tested to ensure nonintermittent, sufficient wireless power transfer, with the lowest possible density. In this way, it is possible to comply with maximum transfer efficiency and minimum EM interference and pollution, at the same time. Typical frequencies adopted for these purposes are in the UHF and SHF bands around 400-800 MHz, for terrestrial TV signals, and around 900, 1800, 2400 and 5800 MHz, for different wireless standards: since the geometrical area to be covered are usually of the order of few meters, the devices to be powered are in the far-field region of their known or unknown RF/microwave sources. This article reviews some of the recent and promising circuit and antenna solutions and discusses reliable sub-systems adopted for receiving and transmitting subsystems, their associated radiating elements, with a focus on minimizing the power budget for enabling device operations.

Thanks to the quality of the technology and the existence of international standards, wireless communication networks (based on radio-frequency RF radiation) nowadays underpin the global functioning of our societies. The pursuit towards higher spectral efficiency has been around for about 4 decades, with 5G expected in 2020. 5G and beyond will see the emergence of trillions of low-power autonomous wireless devices for applications such as ubiquitous sensing through an Internet of Things (IoT).Wireless is however more than just communications. For very short range, wireless power via Inductive Power Transfer is a reality with available products and standards (Wireless Power Consortium, Power Matters Alliance, Alliance for Wireless Power, Rezence). Wireless Power via RF (as in wireless communication) on the other hand could be used for longer range via two different ways, commonly referred to as wireless energy harvesting (WEH) and (farfield or radiative) wireless power transfer/transmission (WPT). While WEH assumes RF transmitters are exclusively designed for communication purposes whose ambient signals can be harvested, WPT relies on dedicated sources designed exclusively for wireless power delivery. Wireless Power via RF has long been regarded as a possibility for energising lowpower devices, but it is only recently that it has become recognised as feasible. Indeed, according to , at a fixed computing load, the amount of requested energy falls by a factor of two every year and a half due to the evolution of the electrical efficiency of computer technology. This explains why relying on wireless power to perform meaningful computation tasks at reasonable distances only became feasible in the last few years and justifies this recent interest in wireless power.Recent research advocates that the future of wireless networking goes beyond conventional communication-centric transmission. In the same way as wireless (via RF) has disrupted mobile communications for the last 40 years, wireless (via RF) will disrupt the delivery of mobile power. However, current wireless networks have been designed for communication purposes only. While mobile communication has become a relatively mature technology, currently evolving towards its fifth generation, the development of mobile power is in its infancy and has not even reached its first generation. Not a single standard on mobile power and far-field WPT exists.Despite being subject to regulations on exposure to electromagnetic fields as wireless communication, wireless power brings numerous new opportunities. It enables proactive and controllable energy replenishment of devices for genuine mobility so that they no longer depend on centralised power sources. Hence, no wires, no contact, no (or at least reduced) batteries (and therefore smaller, lighter and compact devices), an ecological solution with no production/maintenance/disposal of trillions of batteries, a prolonged lifetime and a perpetual, predictable and reliable energy supply as opposed to ambient energy-harvesting tec...

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Energizing 5GW e are surrounded in our daily lives by a multitude of small, relatively inexpensive computing devices, many equipped with communication and sensing features. From these has evolved the concept of "pervasive intelligence" [1], [2], a basis from we can envision our future world as an Internet of Things/Internet of Everything (IoT/IoE), in terms of both a consumer IoT/ IoE (interconnected devices within an individual's environment) and the Industrial IoT (interconnectedness to improve business-to-business services, mainly through machine-to-machine interactions) [3].Decades of research have produced a plethora of devices for a variety of application domains, devices that do not always share common standards and communication requirements. It is envisioned that the advent of fifth-generation (5G) communication networks will bring together all these requirements by integrating multiple heterogeneous access technologies. Moreover, 5G's goals of increased data rates, reduced end-to-end latency, and improved coverage [4] will support an exponentially greater number devices with reduced cost per information transfer, thus making our vision for the IoT/IoE feasible in practice. Achieving these goals, will force future 5G networks to rely on a multitier architecture starting from the macrocell level and moving up to device-to-device (D2D) micronetworks [5]. In this article, we focus on XXXXXXX

In this work, a flexible and extensive digital platform for Smart Homes is presented, exploiting the most advanced technologies of the Internet of Things, such as Radio Frequency Identification, wearable electronics, Wireless Sensor Networks, and Artificial Intelligence. Thus, the main novelty of the paper is the system-level description of the platform flexibility allowing the interoperability of different smart devices. This research was developed within the framework of the operative project HABITAT (Home Assistance Based on the Internet of Things for the Autonomy of Everybody), aiming at developing smart devices to support elderly people both in their own houses and in retirement homes, and embedding them in everyday life objects, thus reducing the expenses for healthcare due to the lower need for personal assistance, and providing a better life quality to the elderly users.