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Abstract-In this paper, inkjet-printed flexible sensors fabricated on paper substrates are introduced as a system-level solution for ultra-low-cost mass production of UHF Radio Frequency Identification (RFID) Tags and wireless sensor nodes in a "green" approach that could be easily extended to other microwave and wireless applications. The authors briefly touch up the state-of-the-art area of fully integrated wireless sensor modules on paper and show several active and power scavenging platforms to power on wireless sensors that could potentially set the foundation for the truly convergent wireless sensor ad hoc networks of the future.Plus, the authors address the integration of carbon-nanotubes on paper substrates for the realization of ultra sensitive (parts per billion) gas sensors and present benchmarking results for various scavenging approaches involving solar and charge transfer-based mechanisms. Various challenges of packaging, passives, antennas, sensors and power sources integration are investigated in terms of ruggedness, reliability and flexibility performance for space, automotive, "smart-skin" and wearable applications.

We have developed some low-cost predistortion circuits to compensate second-and third-order laser distortions in multiservice radio-over-fiber industrial systems. Depending on the predistorter configuration implemented, average reductions of 10-15 dB and of 8-10 dB have been observed in the laser secondand third-order distortions, respectively, within the cellular bands relevant to the European TETRA, GSM, and DCS standards. In particular, the development of the prototypes here illustrated is based on a new and original procedure that formalizes and suitably integrates in a sinergistic way modeling, design, and experimental activities.

The inclusion of lumped elements, both linear and nonlinear, into the finite-difference time-domain (FDTD) algorithm has been recently made possible by the introduction of the lumped-element FDTD method. Such a method, however, cannot efficiently and accurately account for two-terminal networks made of several lumped elements, arbitrarily connected together. This limitation can be removed as proposed in this paper by describing the network in terms of its impedance in the Laplace domain and by using appropriate digital signalprocessing methodologies to fit the resulting description to Yee's algorithm. The resulting difference equations allow an arbitrary two-terminal network to be inserted into one FDTD cell, preserving the full explicit nature of the conventional FDTD scheme and requiring a minimum number of additional storage variables. The new approach has been validated by comparison with the exact solution of a parallel-plate waveguide loaded with lumped networks in the transverse plane.

No Battery RequiredO ver the last decade, radio frequency identification (RFID) systems have been increasingly used for identification and object tracking due to their low-power, low-cost wireless features. In addition, the explosive demand for ubiquitous rugged low-power, compact wireless sensors for Internet-of-Things, ambient intelligence, and biomonitoring/quality-of-life application has sparked a plethora of research efforts to integrate sensors with an RFID-enabled platform. The rapid evolution of large-area electronics printing technologies (e.g., ink-jet printing and gravure printing) has enhanced the development of low-cost RFID-enabled sensors as well as accelerated their large-scale deployment. This article presents a