Co-Design Strategies for Energy-Efficient UWB and UHF Wireless Systems

This paper reviews the most recent methods, combining nonlinear harmonic-balance-based analysis with electromagnetic (EM) simulation, for optimizing, at the circuit level, modern radiative RF/microwave systems. In order to maximize the system efficiency, each subsystem must be designed layoutwise, accounting for the presence of the others, that is, accounting for its actual terminations, rather than the ideal ones (50 Ω). In this way, the twofold goal of minimizing size and losses of the system is obtained by reducing intersystem matching networks. Indeed, terminations are complex, frequency-dispersive, and variable with the signal level, if active operations are concerned, and are responsible for performance degradation if not properly optimized. This approach is nowadays necessary, given the ever increased spread of pervasively distributed RF microsystems adopting miniaturized antennas, such as radio frequency identification (RFID) or wireless sensor networks, that must be low-cost, low-profile, low-power, and must simultaneously perform localization, identification, and sensing. For the design of a transmitter and a receiver connected with the respective antennas, suitable figures of merit are considered, encompassing radiation and nonlinear performance. Recent representative low-profile realizations, adopting ultra-wideband (UWB) excitations are used to highlight the benefit of the proposed nonlinear/EM approach for next generation energy autonomous microsystem, such as UWB-RFID tags

Archaeometric analysis for provenance and content of Roman amphorae from the site of Sa Mesquida (Mallorca, Spain)

This paper presents the results of an inorganic and organic approach to Roman amphorae found at the rural Roman site of Sa Mesquida (Mallorca). A set of amphorae were discovered in some rooms of the earlier phases of the villa. These amphorae were assigned to a general Tarraconensian and Italic provenance on a macroscopic level. In order to verify this and to accurately determine the provenance an archaeometric characterization was carried out on twelve amphorae. The analytical approach combined wavelength dispersive X-ray fluorescence (WD-XRF) for the chemical analysis, as well as powder x-ray diffraction (XRD) and optical microscopy by thin-section analysis (OM) for the mineralogical and petrographic characterization. In addition, organic residue analysis by gas-chromatography mass spectrometry (GC-MS) was applied to investigate the content of some of the amphorae for which wine was suggested on an archaeological basis. The results have allowed for a better provenance determination identifying some amphorae from specific workshops or micro-regions within ancient Tarraconensis, as well as a better definition of the Italic materials. The organic analysis has confirmed the presence of wine in the analysed samples

Endogenous CCL2 neutralization restricts HIV-1 replication in primary human macrophages by inhibiting viral DNA accumulation

Macrophages are key targets of HIV-1 infection. We have previously described that the expressionof CC chemokine ligand 2 (CCL2) increases during monocyte differentiation to macrophages and it is furtherup-modulated by HIV-1 exposure. Moreover, CCL2 acts as an autocrine factor that promotes viral replication ininfected macrophages. In this study, we dissected the molecular mechanisms by which CCL2 neutralization inhibitsHIV-1 replication in monocyte-derived macrophages (MDM), and the potential involvement of the innate restrictionfactors protein sterile alpha motif (SAM) histidine/aspartic acid (HD) domain containing 1 (SAMHD1) and apolipoproteinB mRNA-editing, enzyme-catalytic, polypeptide-like 3 (APOBEC3) family members.Results:CCL2 neutralization potently reduced the number of p24 Gag+cells during the course of either productive orsingle cycle infection with HIV-1. In contrast, CCL2 blocking did not modify entry of HIV-1 based Virus Like Particles, thusdemonstrating that the restriction involves post-entry steps of the viral life cycle. Notably, the accumulation of viralDNA, both total, integrated and 2-LTR circles, was strongly impaired by neutralization of CCL2. Looking for correlates ofHIV-1 DNA accumulation inhibition, we found that the antiviral effect of CCL2 neutralization was independent of themodulation of SAMHD1 expression or function. Conversely, a strong and selective induction of APOBEC3A expression,to levels comparable to those of freshly isolated monocytes, was associated with the inhibition of HIV-1 replicationmediated by CCL2 blocking. Interestingly, the CCL2 neutralization mediated increase of APOBEC3A expression was typeI IFN independent. Moreover, the transcriptome analysis of the effect of CCL2 blocking on global gene expressionrevealed that the neutralization of this chemokine resulted in the upmodulation of additional genes involved in thedefence response to viruses.Conclusions:Neutralization of endogenous CCL2 determines a profound restriction of HIV-1 replication in primaryMDM affecting post-entry steps of the viral life cycle with a mechanism independent of SAMHD1. In addition, CCL2blocking is associated with induction of APOBEC3A expression, thus unravelling a novel mechanism which mightcontribute to regulate the expression of innate intracellular viral antagonistsin vivo. Thus, our study may potentially leadto the development of new therapeutic strategies for enhancing innate cellular defences against HIV-1 and protecting macrophages from infection

An Ultra-wideband Battery-less Positioning System for Space Applications

An ultra-wide bandwidth (UWB) remote-powered positioning system for potential use in tracking floating objects inside space stations is presented. It makes use of battery-less tags that are powered-up and addressed through wireless power transfer in the UHF band and embed an energy efficient pulse generator in the 3-5 GHz UWB band. The system has been mounted on the ESA Mars Rover prototype to demonstrate its functionality and performance. Experimental results show the feasibility of centimeter-level localization accuracy at distances larger than 10 meters, with the capability of determining the position of multiple tags using a 2W-ERP power source in the UHF RFID frequency band.Comment: Published in: 2019 IEEE International Conference on RFID Technology and Applications (RFID-TA

UWB-UHF RFID TAG ON PAPER FOR SIMULTANEOUS COMMUNICATION AND RF ENERGY HARVESTING

This paper presents the design of a compact integrated UWB-UHF RFID solution enabling simultaneous wireless data and power transfer. The described integrated dual-band antenna is designed to cover the lower European UWB 3.1 to 4.8 GHz band for communication and localization functions and the European UHF RFID 868 MHz band for RF Energy Harvesting. Simultaneous operations are guaranteed by means of a proper feeding and matching network, a three-port diplexer, in a compact, low-profile solution. In order to fulfil eco-compatibility requirements, both the radiating system and the matching network are designed on paper substrate

Rectenna Array with RF-Uncoupled Closely-spaced Monopoles for Autonomous Localization

The crucial role of a decoupling/matching network is demonstrated for the design of a compact 868-MHz double-antenna energy harvester, driving two different rectifiers branches for the efficient powering of a wake-up radio (WUR)-enabled localization node. Two highly-coupled meandered cross-polarized monopoles, located in close proximity, are adopted for orientation-insensitive operations, thus requiring the design of a RF-decoupling and matching network before rectification. The superior performance of the two-element harvester with respect to a standard single-monopole rectenna is experimentally demonstrated in different conditions: it justifies the deployment of the presented tag for the energy autonomy of future generation RFID tags for indoor localization

A multilayer compact-size UWB-UHF antenna system for novel RFID applications

Hybrid UWB-UHF antennas are deemed important for combining localization with energy harvesting. This paper enhances the design of existing work and proposes a new dual-band small-size/low-profile device for simultaneous RF energy harvesting as well as communication and localization functions. This is achieved by having the localization provided in the lower European UWB band 3.1 to 4.8 GHz, while the RF energy is harvested in the UHF RFID 868 MHz band; thus dealing with less path losses with respect to higher frequency harvesting systems (e.g. ISM band), i.e. resulting in more available RF power. Electromagnetic and nonlinear circuit simulation shows that only 43 743 76 mm3 in dimensions is needed for this dual band antenna with RF to DC conversion efficiency in the range of 50-60%, which is state-of-The-Art performance for exploiting the capabilities of such antennas. Implementation of this antenna, including matching/feeding circuitry, is under development to prove real-indoors performance

Low-cost UHF near-field power transmission for RFID applications

Nowadays, the average age of the world population is progressively rising; consequently, several individuals are diagnosed with age-related illnesses and require to be monitored and assisted continually, both in their own houses and in retirement homes. In addition, it\u2019s demonstrated that the early detection of disorders such as Alzheimer\u2019s disease, major depression or other types of senile dementia, can be accomplished by analyzing the movements and the behavior of high-risk patients. In this work, we describe a 2.45 GHz RFID reader, exploiting the Monopulse RADAR capabilities for an electronic mono-dimensional beam-steering, in order to simultaneously track multiple tagged entities, static or dynamic, located in harsh electromagnetic environments. In addition, a system of inertial sensors, such as accelerometers and gyroscopes, is also illustrated: thanks to the combination of these two technologies, long-term people habits and ambient occupancy can be accurately evaluated in typical indoor scenarios. This amount of data can be collected and exploited for various feedbacks both by the family members and the medical team to assist the patients for an early diagnosis and care

Quasi-Isotropic RF Energy Harvester for Autonomous Long Distance IoT Operations

A UHF energy harvesting unit, also comprising UWB communication function, is integrated in a low-profile, compact, unique device. The optimized collocation of two couples of dual linearly-polarized dipoles provides all-polarization receiving capability and a quasi-isotropic radiation, momentous features for RF energy harvesting applications. Activation distance of a commercial ultra-low power management unit is enhanced with respect to a corresponding single-rectenna case. The EM-based non-linear simulation of the entire system has shown its ability to rectify RF power incident from any direction, with activation distances always higher than 14.7 meters for any direction of arrival and up to 26 meters in the best-case condition. Im-plementation of the presented RF harvester outperforms the cor-responding single-dipole harvester realization in a real indoor scenari