192 research outputs found

    Simulation and measurement of quasi-optical multipliers

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    Design of a patch antenna with thermo-electric generator and solar cell for hybrid energy harvesting

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    The design and the radiation performances of performances of a novel hybrid Energy Harvesting ( Energy Harvesting (Energy Harvesting (EH ) and wireless communication system based on a quarter-wave patch wave patch antenna with integrated modules for EH applications are documented in this paper. A Thermo-Electric Generator (TEG) and a Solar Cell (SC) are used in order toare used in order to harvest concurrently thermal and solar energy providing a hybrid EH system system system. The antenna, with the harvesting modules harvesting modules stacked on it, operates in the the the Industrial, Scientific and Medical (ISM) frequency band 2.4-2.48 GHz showing a reflection coefficient below the -10 dB and a maximum gain of about 2.6 dB. The antenna can be used for wireless of about 2.6 dB. The antenna can be used for wireless of about 2.6 dB. The antenna can be used for wireless of about 2.6 dB. The antenna can be used for wireless of about 2.6 dB. The antenna can be used for wireless of about 2.6 dB. The antenna can be used for wireless of about 2.6 dB. The antenna can be used for wireless of about 2.6 dB. The antenna can be used for wireless of about 2.6 dB. The antenna can be used for wireless communication or, alternatively, to perform Electro-Magnetic (EM) energy scavenging by mounting a voltage rectifier at its terminals

    Performance analysis of a ultra-compact low-power rectenna in paper substrate for RF energy harvesting

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    In this paper the experimental results of a compact low-power rectenna in paper substrate, designed to operate in the Wi-Fi band, are presented. The complete prototype, based on an annular slot antenna and a single-diode rectifier, features a weight of 1.5 grams and shows an RF-to-dc conversion efficiency in the design band of about 40 % for a -10 dBm available input power, of about 28 % at -15 dBm, and in the range [10, 22] % at -20 dBm, corresponding to an output DC voltage in the order of 320, 240 and 60 mV respectively. Additionally, the rectenna features an efficiency higher then 7 % in the whole band 1.8-2.7 dBm for a power density estimated around 3 ΌW/cm2.Grant numbers : The work was supported by the EU COST Action IC1301 WiPE (Wireless Power Transmission for sustainable Electronics). © 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works

    Innovative RFID Sensors for Internet of Things Applications

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    Radio-Frequency IDentification (RFID) devices and sensors are among the main innovations of the last years, with an enormous impact on the Internet of Things (IoT) physical communication layer as well as on logistics and robotics. The aim of the present paper is to review the main technologies available for RFID sensors, and to identify the corresponding state-of-the-art when these technologies are applied to realistic IoT scenarios. Firstly, the concepts of radio backscattering and harmonic backscattering are analyzed, highlighting the pros and cons of each approach. Then, state-of-the-art solutions are reported, and the performance of each of them are discussed, to provide an overview of the potential of RFID-based sensing in different scenarios

    3-D-Printing-Based Selective-Ink-Deposition Technique Enabling Complex Antenna and RF Structures for 5G Applications up to 6 GHz

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    This paper introduces a novel additive-manufacturing technique to obtain high-resolution selective-ink-deposition on complex 3-D objects, packages, and modules for 5G applications. The technique consists of embossing the desired pattern directly on the 3-D printed dielectric surface and then applying ink with a suitable tool. This approach is tested in combination with stereolithography 3-D printing technology to obtain selectively metallized 3-D circuits. In particular, the "clear" resin from FormLab is utilized for the 3-D printed dielectric, while the metallization is performed with silver nanoparticle ink from Suntronic. As a preliminary study, test samples containing lines with different widths are manufactured, demonstrating a pitch down to 135 Όm135~\mu \text {m} and satisfactory sheet resistance of 0.011 Ω/sq.0.011~\Omega /\text {sq.} (the electromagnetic characterization of the dielectric resin is reported in the Appendix). Then, two broadband multiport RF structures are developed to show the versatility of the proposed technology. First, an ultrawideband 3-D crossover, operating in the range 100 MHz–5 GHz, is conceived to test the suitability of the proposed technology to perform selective metallization on curved semienclosed areas. Then, the technology is applied to a multiple-input–multiple-output (MIMO) antenna system, based on four proximity-fed annular slot antennas, arranged on the lateral sides of a cube and decoupled by introducing a cross-shaped structure in the interior of the cube. This circuit offers a broad range of metallization challenges, as it features embossed and engraved parts, high-resolution patterns (line widths down to 0.7 mm) and sharp edges. Each slot radiates unidirectionally with the same polarization and uses the cube and its internal cross-shaped structure as a resonant cavity. The antenna system is designed to operate in the band 3.4–3.8 GHz, which is one of the sub-6-GHz 5G bands in Europe, and it is thought for hotspot and access-point applications. The final antenna topology is composed of only two blocks, weighs 21.29 g, and occupies a volume of 44.4×45.8×45.8  mm344.4\times 45.8\times 45.8\,\,\text {mm}^{3} , featuring an envelope correlation coefficient (ECC) lower than 0.005 and a total active reflection coefficient (TARC) lower than −6 dB in all the bands of interests

    L’inconsistenza della diagnosi di cancro duttale in situ

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    Background: Classifying ductal carcinoma in situ (DCIS) remains problematical for interpretation of specified histological features and field selection where morphology is heterogeneous. Emphasis is placed on the role of intraductal proliferative lesions as risk factors of variable magnitude in subsequent development of invasive breast carcinoma. The present study is designed to investigate the relative contribution of diagnostic and treatment paradigms on the lack of consistency in the analysis of these lesions. Materials and methods: A cohort of in situ lesions of the breast was reviewed according to ductal intraepithelial neoplasia (DIN) classification adopted by the World Health Organization (WHO). In this retrospective study 458 patients with DIN diagnosed by core needle biopsy had undergone conservative or radical surgical treatment and SLNB in cases of DIN1C-DIN3. Results: Breast conservative surgery was the definitive treatment in 80% of cases. All the SLNs sampled showed 1.2 % (4/336) positivity of metastatic or micrometastatic nodal involvement by H&E stain while the IHC assessment for cytokeratin showed 4.5% (15/336) positivity. Conclusions: The widely recognised variation in the growth pattern of DCIS makes difficult to identify uniform indications for clinical procedure. Although the incidence of metastases in patient with initial diagnosis of DIN is considered to be low, SLNB remains an attractive option to guarantee oncological safety. In patients at high risk occult invasion does occur and without lymphatic analysis, undertreatment is possible

    Untailored vs. Gender- and Body-Mass-Index-Tailored Skeletal Muscle Mass Index (SMI) to Assess Sarcopenia in Advanced Head and Neck Squamous Cell Carcinoma (HNSCC)

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    : (1) background: sarcopenia lasting >1 year might be considered a chronic condition in many HNSCC patients. CT-scan-derived skeletal muscle mass Index (SMI) is an established surrogate of sarcopenia; yet, the cut-off reported in the literature (literature-based, lb-SMI < 43.2) is mainly based on the risk of chemoradiotherapy-induced toxicity, and the optimal value to discriminate OS is under-investigated. (2) methods: the effect on OS of the lb-SMI cutoff was compared with an untailored OS-oriented SMI cutoff obtained in a cohort of consecutive advanced HNSCC patients treated with primary chemoradiotherapy, bio-chemotherapy or chemo-immunotherapy (cohort-specific, cs-SMI cutoff). gender- and BMI-tailored (gt-SMI and bt-SMI) cut-offs were also evaluated. cutoff values were identified by using the maximally selected rank statistics for OS. (3) results: In 115 HNSCC patients, the cs-SMI cutoff was 31.50, which was lower compared to the lb-SMI reported cut-off. the optimal cut-off separately determined in females, males, overweight and non-overweight patients were 46.02, 34.37, 27.32 and 34.73, respectively. gt-SMI categorization had the highest effect on survival (p < 0.0001); its prognostic value was independent of the treatment setting or the primary location and was retained in a multivariate cox-regression analysis for OS including other HNSCC-specific prognostic factors (p = 0.0004). (4) conclusions: a tailored SMI assessment would improve clinical management of sarcopenia in chemoradiotherapy-, bio-chemotherapy- or chemo-immunotherapy-treated HNSCC patients. gender-based SMI could be used for prognostication in HNSCC patients
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