"Phoenix' reflectarray unit cell with reduced size and inductive loading

This study presents a new Phoenix unit cell with reduced size (l0/3 at centre frequency). Three different techniques are investigated to preserve a complete 360° phase range, with quasi-linear and parallel phase responses over a reasonable frequency band, in spite of this small size. The phase cycle successively uses two different printed elements with complementary capacitive and inductive responses. The studied techniques aim at increasing the insufficient inductive effect. As a demonstration, a 1877-element reflectarray is fabricated with the technique compatible with a single-substrate fabrication process. Measured results show a 1 dB gain bandwidth of 11.3%.Makdissy, T.; Gillard, R.; Fourn, E.; Ferrando Rocher, M.; Girard, E.; Legay, H.; Le Coq, L. (2016). "Phoenix' reflectarray unit cell with reduced size and inductive loading. IET Microwaves Antennas and Propagation. 10(12):1363-1370. doi:10.1049/iet-map.2015.0626S13631370101

New results from the SoftLAB benchmark of antenna software

This paper gives an overview of the antenna software benchmarking activity that took place within the Software Group of the EurAAP association in 2009. A particular focus is brought to one of the proposed test case that consists of a non conventional horn antennaPostprint (published version

Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial

Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie

Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial

Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049

Schémas multigrilles pour la méthode des différences finies dans le domaine temporel(FDTD) (Application à la simulation de réseaux corporels sans fil (WBAN))

Les réseaux corporels sans fil (WBAN pour Wireless Body Area Network) consistent en un ensemble d'objets communicants placés directement sur ou à l'intérieur du corps humain. Les domaines d'application sont variés et s'étendent du domaine médical au domaine militaire en passant par les loisirs. Les travaux de cette thèse ont été consacrés au développement de nouvelles techniques de simulation électromagnétique dédiées à l'analyse rapide et précise de la transmission des ondes radio entre les objets communicants d'un réseau WBAN. Face à la nature tridimensionnelle et inhomogène du milieu de propagation, la méthode des différences finies dans le domaine temporel (FDTD) s'est avérée la mieux adaptée pour résoudre ce genre de problème. Cependant, sous sa forme classique, cette méthode impose un schéma de maillage uniforme qui rend les simulations coûteuses en ressources informatiques.Deux nouveaux schémas multigrilles en FDTD sont proposés dans cette thèse. Ces schémas sont basés sur la division du problème global en sous-volumes FDTD indépendants permettant de caractériser chaque élément à l'aide d'un maillage approprié. Le transfert de l'information électromagnétique entre les volumes est assuré par l'utilisation de surfaces de prélèvement et d'excitation. Ainsi les schémas proposés sont stables. Après avoir validé ces nouvelles approches sur des cas simples, elles sont appliquées à la simulation de problèmes complexes et réalistes. La transmission entre une antenne implantée dans le corps humain et un dipôle en espace libre est tout d'abord analysée. Différentes postures du corps ainsi que différents environnement de propagation sont considérés. Le canal de propagation sur le corps humain est ensuite caractérisé à l'aide de deux antennes disposées sur le corps. Enfin, le débit d'absorption spécifique à 900 MHz dans le cerveau d'un fœtus est calculé à l'aide d'un modèle numérique de femme enceinte.This thesis aims at developing new Finite Difference Time Domain (FDTD) schemes for the fast and accurate simulation of Wireless Body Area Network problems. This emerging technology consists of several body sensors placed on or inside the body. The application range is wide. It concerns medical, entertainment and military domains. The FDTD is an efficient numerical technique for analysing waves propagation in complex environments such as the human body. However, it involves a uniform cubic grid, which leads to time consuming simulations. Two multigrid FDTD schemes are proposed in this thesis. They are based on the principle of dividing the general problem into independent FDTD sub-volumes which aim at characterising each element with an appropriate mesh. The electromagnetic information transfer is realised by the use of near-field and excitation surfaces. Thus, the proposed schemes are stable. These approaches are first validated using canonical examples. Then, they are applied to the simulation of complex and more realistic problems. The transmission between an implanted antenna and a simple dipole is firstly analysed. Several body postures and environment are considered. The WBAN on-body channel is then characterised by use of two antennas placed on the body surface. Finally, the specific absorption rate is calculated at 900 MHz in the fetal brain of a numerical pregnant woman model.RENNES-INSA (352382210) / SudocSudocFranceF

A general equivalent circuit model for Phoenix cells

International audienceThis communication proposes a general equivalent circuit model for the fast characterization of Nth-order Phoenix cells. It provides an intuitive and comprehensive quasi-analytic description of the Phoenix cellsand#x2019; electrical behavior through static lumped reactive elements representation. Given the quasi-analytic nature of the model, it can be exploited in a pre-dimensioning phase. The model proves to give good qualitative accordance with respect to full-wave simulations; statistical analysis on a large set of geometries demonstrates the model efficiency and generality. IEE

A Dual-Band Dual-Circular-Polarization Antenna for Ka-Band Satellite Communications

A novel Ka-band dual-band dual-circularly-polarized antenna array is presented in this letter. A dual-band antenna with left-hand circular polarization for the Ka-band downlink frequencies and right-hand circular polarization for the Ka-band uplink frequencies is realized with compact annular ring slots. By applying the sequential rotation technique, a 2 × 2 subarray with good performance is obtained. This letter describes the design process and presents simulation and measurement results

A Reflector Antenna with Integrated Frequency-Selective Metal-Only Reflectarray for Dual-Band Operation

International audienceThis paper presents a dual-band metal-only antenna that operates at 20 and 40 GHz. The unit cell consists of a square waveguide with short circuit termination and a square metallic block in the center. Its performance is evaluated and analyzed in detail. The proposed metal-only antenna combines the functionalities of reflectarray and parabolic reflector antennas. At 20 GHz, the reflected beam is determined by a parabolic surface. At 40 GHz, the reflected beam is controlled by the phase distribution of cells in the antenna. The gain increases with frequency in the lower frequency band, which is similar to what happens in a parabolic reflector antenna. The antenna profile is significantly reduced and the antenna&#039;s performance is improved after rotating the coordinate system. The antenna with reduced profile is fabricated using selective laser melting 3D printing technology. The measured results show that the proposed antenna can operate as parabolic reflector and reflectarray in the target two frequency bands. © 2013 IEEE

Three-dimensional metal-only phoenix cell and its application for reflectarrays

International audienceA 3D metal-only waveguide-based phoenix cell for reflectarray is presented. The proposed cell consists of two concentric square waveguides and a metallic block in the centre, which offers two operation modes. The first mode uses its cross section to tune reflection phase while the second mode varies the heights of two waveguides to manipulate reflection phase. The principle of the two different modes is analysed in detail. A metal-only reflectarray antenna at 20 GHz is designed based on the first mode of the phoenix cell. It is fabricated using selective laser melting 3D printing technology. A good agreement between simulations and measurements is achieved. The measured gain at 19.75 GHz is 30.25 dBi with an aperture efficiency of 51.17% respectively. Also, the measured 1-dB gain bandwidth is 15% (19-22 GHz). A dual band metal-only reflectarray operating at 20 and 25 GHz is designed based on the second mode of the phoenix cell. The two metal-only reflectarray antennas fully demonstrate the capabilities of the proposed 3D metal-only phoenix cell. A 3D metal-only waveguide-based phoenix cell for reflectarray, offering two operation modes for reflection phase manipulation is presented. A metal-only reflectarray antenna at 20 GHz is designed and fabricated using selective laser melting 3D printing technology, showing good agreement between simulations and measurements. Additionally, a dual band metal-only reflectarray operating at 20 and 25 GHz is designed based on the second mode of phoenix cell.imag