Sidelobe level correction for parabolic antennas radiation pattern measurements in quasi-far-field conditions

A method and formulae for correction of the sidelobe level of the radiation pattern of a high gain antenna when measured in the Fresnel region are presented. After a thorough analysis of a large number of different cases, trend curves have been computed and an empirical formula has been derived, which allows the correction of the measured values of the sidelobes when the measurement range is below or around the far-field distance

Single-Layer, Multi-Mode OAM Reflectarray Antennas

In this letter, an innovative ReflectArray (RA) antenna able to radiate in the same direction multiple Orbital Angular Momentum (OAM) modes, is presented: depending on the direction of arrival of the impinging field, the RA radiates a broadside beam carrying on an OAM mode with different index. Two circular RAs with diameter D = 19.8λ at the the frequency f0 = 30 GHz, able to radiate two or four OAMs, have been designed and simulated, while a prototype of the dual-mode configuration has also been manufactured and experimentally characterised. The obtained results prove that vortex beams are successfully generated in the range of frequencies from 28 to 32 GHz, confirming the effectiveness of the proposed design

An ICRF strap antenna solution exploiting the high impedance technique

Ion Cyclotron Range of Frequencies (ICRF) strap antennas are routinely adopted in most of the existing nuclear fusion experiments, even though their main goal, i.e. to couple high power to the plasma (MW), is often limited by rather severe drawbacks due to high fields on the antenna itself and on unmatched part of the feeding lines directly connected to the antenna. In this work, we propose, describe, prototype and measure an ICRF strap antenna based on the high impedance surfaces concept that is matched at a specific tunable frequency. The adopted high-impedance structure, positioned between the strap and the backwall, is a metallic patch displaced on top of a dielectric block and grounded by means of a vertical post, in a mushroom-like shape. This structure presents a high impedance, within a given very narrow frequency band, such that the image currents are in-phase with the currents of the strap itself, thus determining a significant efficiency increase. After a general description on the properties of high impedance surfaces applied to ICRF antennas, we describe the optimization steps, carried on by means of numerical codes, to define an antenna configuration suitable for a nuclear fusion experiment. The antenna has been then manufactured and measured; strengths and weaknesses of the proposed solution are outlined

Multifocal Approach for Reflectarray Antenna for DTH Applications

In this paper, numerical and experimental results on the design of a multifocal, planar Reflectarray with scanning capabilities in both elevation and azimuth, are presented. The antenna is a possible alternative to the conventional parabolic reflectors in Direct-To-Home (DTH) receiving systems, with the planar reflector fixed to a building wall and the pointing obtained mechanically moving the feed to steer the main beam of the reflectarray

Additive Manufacturing Technology for High Performances Feed Horn

In this work the design and manufacturing through selective laser melting technology of single-band dual circular feed-system operating in Ka-band is reported. In the feed design an AM oriented architecture has been employed. The measured performances confirms the good manufacturing of the system that satisfies very stringent requirements in terms of polarization purity

Read-through transcripts in normal human lung parenchyma are down-regulated in lung adenocarcinoma

Read-through transcripts result from the continuous transcription of adjacent, similarly oriented genes, with the splicing out of the intergenic region. They have been found in several neoplastic and normal tissues, but their pathophysiological significance is unclear. We used high-throughput sequencing of cDNA fragments (RNA-Seq) to identify read-through transcripts in the non-involved lung tissue of 64 surgically treated lung adenocarcinoma patients. A total of 52 distinct read-through species was identified, with 24 patients having at least one read-through event, up to a maximum of 17 such transcripts in one patient. Sanger sequencing validated 28 of these transcripts and identified an additional 15, for a total of 43 distinct read-through events involving 35 gene pairs. Expression levels of 10 validated read-through transcripts were measured by quantitative PCR in pairs of matched non-involved lung tissue and lung adenocarcinoma tissue from 45 patients. Higher expression levels were observed in normal lung tissue than in the tumor counterpart, with median relative quantification ratios between normal and tumor varying from 1.90 to 7.78; the difference was statistically significant (P < 0.001, Wilcoxon's signed-rank test for paired samples) for eight transcripts: ELAVL1-TIMM44, FAM162B-ZUFSP, IFNAR2-IL10RB, INMT-FAM188B, KIAA1841-C2orf74, NFATC3-PLA2G15, SIRPB1-SIRPD, and SHANK3-ACR. This report documents the presence of read-through transcripts in apparently normal lung tissue, with inter-individual differences in patterns and abundance. It also shows their down-regulation in tumors, suggesting that these chimeric transcripts may function as tumor suppressors in lung tissue

Comparison of reflector antenna measurements and simulations

In antenna measurement, well-established procedures are consolidated to determine the associated measurement uncertainty for a given antenna and measurements scenario [1-2]. Similar criteria for establishing uncertainties in numerical modeling of the same antenna are still to be established. In this paper, we investigate the achievable agreement between antenna measurement and simulation when external error sources are minimized. The test object, is a reflector fed by a wideband dual ridge horn (SR40-A and SH4000) manufactured by MVG. This highly stable reference antenna has been selected to minimize uncertainty related to finite manufacturing and material parameter accuracy. Two frequencies, 10.7GHz and 18GHz have been selected for detailed investigation. The antenna has been measured by several measurement facilities (spherical, cylindrical and planar near field ranges) across Europe in the ? ? ? ? ? ? ? ? activity. The purpose of this intercomparison campaign is the comparison of the different antenna measurement facilities, throughout Europe, considering measurement procedures and uncertainty estimates. The antenna has been simulated using a full CAD model, in step compatible format and using different numerical methods from different software vendor

Prostaglandin E2 stimulates the expansion of regulatory hematopoietic stem and progenitor cells in type 1 diabetes

Hematopoietic stem and progenitor cells (HSPCs) are multipotent stem cells that have been harnessed as a curative therapy for patients with hematological malignancies. Notably, the discovery that HSPCs are endowed with immunoregulatory properties suggests that HSPC-based therapeutic approaches may be used to treat autoimmune diseases. Indeed, infusion with HSPCs has shown promising results in the treatment of type 1 diabetes (T1D) and remains the only "experimental therapy" that has achieved a satisfactory rate of remission (nearly 60%) in T1D. Patients with newly diagnosed T1D have been successfully reverted to normoglycemia by administration of autologous HSPCs in association with a non-myeloablative immunosuppressive regimen. However, this approach is hampered by a high incidence of adverse effects linked to immunosuppression. Herein, we report that while the use of autologous HSPCs is capable of improving C-peptide production in patients with T1D, ex vivo modulation of HSPCs with prostaglandins (PGs) increases their immunoregulatory properties by upregulating expression of the immune checkpoint-signaling molecule PD-L1. Surprisingly, CXCR4 was upregulated as well, which could enhance HSPC trafficking toward the inflamed pancreatic zone. When tested in murine and human in vitro autoimmune assays, PG-modulated HSPCs were shown to abrogate the autoreactive T cell response. The use of PG-modulated HSPCs may thus provide an attractive and novel treatment of autoimmune diabetes