A four-element UWB MIMO antenna using SRRs for application in satellite communications

This paper proposes a method for designing a new ultra wide band (UWB) multiple-input multiple-output (MIMO) antenna with two and four elements. First we presented an ultra-wide band antenna we studied these performances. Then, we studied the application of metamaterials to the design of MIMO antennas for miniaturization and the performance of antennas, in order to guarantee the proper functioning of the MIMO system with a much reduced separation distance between the radiating elements (λ/12), where the coupling can be very weak. The application of these circular double ring SRRs materials on the front plan of the antenna has contributed to the increasing of the antenna performance is studied in terms of S-Parameters, efficiency, diversity gain (DG), radiation properties and envelop correlation coefficient (ECC). It offers advantages such as the reduction of weight and congestion that is beneficial for their integration into satellite communications systems

Rigorous Analysis of the Propagation in Metallic Circular Waveguide with Discontinuities Filled with Anisotropic Metamaterial

In this chapter, we present an extension of the rigorous analysis of the propagation of electromagnetic waves in magnetic transverse (TM) and transverse electric (TE) modes in a metallic circular waveguide partially filled with anisotropic metamaterial. In our analysis, the design of waveguide filters with uniaxial discontinuities is based on the determination of the higher-order modes, which have been analyzed and exploited. Below the cutoff frequency, the back backward waves can propagate in an anisotropic material. The numerical results with our MATLAB code for TM and TE modes were compared to theoretical predictions. Good agreements have been obtained. We analyzed a waveguide filters filled with partially anisotropic metamaterial using the mode matching (MM) technique based on the Scattering Matrix Approach (SMA), which, from the decomposition of the modal fields (TE and TM modes), are used to determine the dispersion matrix and thus the characterization of a discontinuity in waveguide. We extended the application of MM technique to the anisotropic material. By using modal analysis, our approach has considerably reduced the computation time compared to High Frequency Structure Simulator (HFSS) software

Radiation performance enhancement of an ultra wide band antenna using metamaterial band-pass filter

In this paper, a metamaterial structure based on Frequency Selective Surface (FSS) cell is proposed to achieve an isotropic band-pass filtering response. This filter consists of a planar layer formed by a 3×3 metamaterials cell array with transmittive filtering behavior at 3.5 GHz. This design with 45 mm × 45 mm dimension is then integrated in close proximity at distance of 10 mm with an Ultra Wide Band (UWB) antenna to enhance it’ s performances around a 3.5 GHz operating frequency. Simulation results ensure that filter geometry provides the advantage of polarization independency and also exhibits the angular stability up to 45◦ for both Transverse Electric (TE) and Transverse magnetic (TM) modes. More importantly, enhancement in antenna radiation pattern characteristics is illustrated when the planar FSS layer is integrated at a small distance from the radiator. Moreover, antenna gain was improved to 3.22 dBi, adaptation of antenna port (S11) was increased to -53.26 dB and antenna bandwidth reduction to 1.7 GHz is also detected. All these performances make the proposed design as a good choice used to shield signals in UWB wireless applications especially for connected object in 5G

Cylindrical Waveguide on Ferrite Substrate Controlled by Externally Applied Magnetic Field

This paper presents an extension of the formulation of wave propagation in transverse electric (TE) and transverse magnetic (TM) modes for the case of metallic cylindrical waveguides filled with longitudinally magnetized ferrite. The higher order modes were exploited. We externally controlled the cut-off frequency through the application of DC magnetic fields. The numerical results of dispersion diagrams for TE and TM modes were obtained and analyzed. We analyzed a waveguide antenna filled with partially magnetized ferrite using the mode matching (MM) technique based on the TE and TM modes. By using modal analysis, our approach considerably reduced the computation time compared to HFSS. Ferrites are important for various industrial applications, such as circulators, isolators, antennas and filters

Classification and Predictions of Lung Diseases from Chest X-rays Using MobileNet V2

Featured Application: The method presented in this paper can be applied in medical computer systems for supporting medical diagnosis.Abstract: Thoracic radiography (chest X-ray) is an inexpensive but effective and widely used medical imaging procedure. However, a lack of qualified radiologists severely limits the applicability of the technique. Even current Deep Learning-based approaches often require strong supervision, e.g., annotated bounding boxes, to train such systems, which is impossible to harvest on a large scale. In this work, we proposed the classification and prediction of lung pathologies of frontal thoracic X-rays using a modified model MobileNet V2. We considered using transfer learning with metadata leverage. We used the NIH Chest-Xray-14 database, and we did a comparison of performance of our approach to other state-of-the-art methods for pathology classification. The main comparison was by Area under the Receiver Operating Characteristic Curve (AUC) statistics and analyzed the differences between classifiers. Overall, we notice a considerable spread in the achieved result with an average AUC of 0.811 and an accuracy above 90%. We conclude that resampling the dataset gives a huge improvement to the model performance. In this work, we intended to create a model that is capable of being trained, and modified devices with low computing power because they can be implemented into smaller IoT devices

COMPLEX RECTANGULAR FILTER DESIGN USING HYBRID FINITE ELEMENT METHOD AND MODIFIED MULTIMODAL VARIATIONAL FORMULATION

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Muli-UWB Antenna System Design for 5G Wireless Applications with Diversity

In this paper, we propose a compact Multiple Input Multiple Output (MIMO) antenna system with high isolation for wireless applications in 5G connected devices. This MIMO antenna system with the size of 92×88 mm2 consists of two elliptical antennas symmetrically arranged next to each other. Two decoupling methods which are neutralization and Defected Ground Structure (DGS) are applied to ensure diversity of the proposed MIMO antenna. The single and MIMO antennas are simulated and analyzed then fabricated and measured. A good agreement between measurements and simulations is obtained. These configurations, dedicated to covering the 3.4 GHz band -3.8 GHz, have shown very satisfactory performances more than -30 dB in terms of reduction of mutual coupling between the antennas constituting our system. MIMO diversity parameters, such as Envelope Correlation (ECC), Diversity Gain (DG), and total efficiency, are also studied for each proposed MIMO system. Thus, results demonstrate that our two proposed antenna configurations are very suitable for 5G MIMO applications

COMPLEX MODE IN RECTANGULAR WAVEGUIDE FILLED WITH LONGITUDINALLY MAGNETIZED FERRITE SLAB

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Efficient Thoracic aortic aneurysm detection method to prevent potential Acute Aortic Dissection

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