43 research outputs found
Four Identical Elements Triangular Dielectric Resonator Antenna with L-shaped Coaxial Feed for wireless applications
No full text
Theoretical Study of the Input Impedance and Electromagnetic Field Distribution of a Dipole Antenna Printed on an Electrical/Magnetic Uniaxial Anisotropic Substrate
No full textThe present work considers the investigation of the effects of both electrical and magnetic uniaxial anisotropies on the input impedance, resonant length, and fields distribution of a dipole printed on an anisotropic grounded substrate. In this study, the associated integral equation, based on the derivation of the Green’s functions in the spectral domain, is numerically solved employing the method of moments. In order to validate the computing method and the evaluated calculation code, numerical results are compared with available data in the literature treating particular cases of electrical uniaxial anisotropy; reasonable agreements are reported. Novel results of the magnetic uniaxial anisotropy effects on the input impedance and the evaluated electromagnetic field are presented and discussed. This work will serve as a stepping stone for further works for a better understanding of the electromagnetic field behavior in complex anisotropic and bi-anisotropic media
Impact of Microstrip-Line Defected Ground Plane on Aperture-Coupled Asymmetric DRA for Ultra-Wideband Applications
No full textGENERALIZED EXPONENTIAL MATRIX TECHNIQUE APPLICATION FOR THE EVALUATION OF THE DISPERSION CHARACTERISTICS OF A CHIRO-FERRITESHIELDED MULTILAYERED MICROSTRIP LINE
No full textAn Inline V-Band WR-15 Transition Using Antipodal Dipole Antenna as RF Energy Launcher @ 60 GHz for Satellite Applications
No full textThis article demonstrates the design and development of WR-15 transition using an antipodal microstrip dipole antenna at a frequency of 60 GHz for space applications. An inline microstrip line to rectangular waveguide (MS-to-RWG) transition is proposed for the V-band (50–75 GHz) functioning. The RF energy is coupled and launched through an antipodal dipole microstrip antenna. Impedance matching and mode matching between the MS line and dipole are achieved by a quarter wave impedance transformer. This results in the better performance of transitions in terms of insertion loss (IL > −0.50 dB) and return loss (RL < −10 dB) for a 40.76% relative bandwidth from 55.57 GHz to 65.76 GHz. The lowest values of IL and RL at 60 GHz are −0.09 dB and −32.05 dB, respectively. A 50 μm thick double-sided etched InP substrate material is used for microstrip antipodal dipole antenna design. A back-to-back designed transition has IL > −0.70 dB and RL < −10 dB from 54.29 GHz to 64.07 GHz. The inline transition design is simple in structure, easy to fabricate, robust, compact, and economic; occupies less space because the transition size is exactly equal to the WR-15 length; and is prepared using an InP substrate with high permittivity of 12.4 and thickness of 50 μm. Thus, the devices have the lowest insertion loss value and lowest return loss (RL) value, of <−31 dB, as compared to earlier designs in the literature. Therefore, the proposed design has the lowest radiation loss (because of thickness) and highest transmission (about 97% power). Easy impedance matching using only a single-step quarter-wave transformer between the antipodal dipole antenna and 50 Ω microstrip line (avoiding the multi-sections’ demand and microstrip line’s tedious complexity) is needed. Since, when the InP dielectric substrate is inserted in WR-15, the waveguide becomes a dielectric-filled waveguide (DFWG), and its characteristics impedance reduces to 143 Ω from 505 Ω at an operating frequency of 60 GHz. In the proposed transition, no ridge waveguide or waveguide back-short is utilized in WR-15. The microstrip line did not contain any via, fence, window, screw, galvanic structure, post, etc. Hence, the transition is suitable for high-data-rate 5G communications, satellite remote sensing, missile navigation, MIC/MMIC circuits’ characterization, and mm-wave applications. The electrical equivalent model of the proposed design has been generated and validated using an RF circuit simulator and was found to have excellent matching
Adoption of Telemedicine during COVID-19 Pandemic Crisis: A Review of the Literature
No full textDigital health literature has provided significant insights into how telemedicine contributes to improving the quality of healthcare and reducing the cost of healthcare. This research focuses on factors influencing adoption of telemedicine. Moreover, the author identifies the challenges of adopting telemedicine. A total of 20 papers were systematically studied and classified. The results show that telemedicine adoption may be influenced by several factors; the results also revealed that major barriers to telemedicine include poor infrastructure of digitalization, resistance to digital transformation, lack of digital knowledge among doctors and patients
Compact Millimeter-Wave MIMO Antenna for 5G Applications
No full textAn efficient four-elements mmWave multiple-input multiple output (MIMO) antenna is proposed for use in 5G system The proposed MIMO mmWave design operates at 35GHz and occupies an overall volume of 12.5 mm × 12.5 mm × 0.8 mm 3 . This antenna exhibits a good matching impedance at the operating frequency of 35GHz mmWave band, where an isolation greater than 25 dB, envelope correlation coefficient (ECC) less than 0.02, and diversity gain (DG) of around 10dB are obtained. The 4-elements MIMO mmWave antenna also shows a peak gain of 6 dBi with 87% of peak radiation efficiency. The obtained results along with size miniaturization signify that the proposed MIMO antenna is deemed as an appropriate candidate for millimeter wave based wireless applications
Adoption of Telemedicine during COVID-19 Pandemic Crisis: A Review of the Literature
No full textInternational audienceDigital health literature has provided significant insights into how telemedicine contributes to improving the quality of healthcare and reducing the cost of healthcare. This research focuses on factors influencing adoption of telemedicine. Moreover, the author identifies the challenges of adopting telemedicine. A total of 20 papers were systematically studied and classified. The results show that telemedicine adoption may be influenced by several factors; the results also revealed that major barriers to telemedicine include poor infrastructure of digitalization, resistance to digital transformation, lack of digital knowledge among doctors and patients
Gyro-Chirality Effect of Bianisotropic Substrate On the operational of Rectangular Microstrip Patch Antenna
No full textYesIn this paper, the gyrotropic bi-anisotropy of the chiral medium in substrate
constitutive parameters (ξc and ηc) of a rectangular microstrip patch antenna is introduced in
order to observe its effects on the complex resonant frequency, half-power bandwidth and
input impedance. Numerical calculations and analysis based on the dominant mode are
carried out to show that the latter is directly related to the former. This paper is based on the
Moment Method as full-wave spectral domain approach using sinusoidal basis functions. Two
new results, namely the appearance of the difference (ξc-ηc) and sum (ξc+ηc) of the two
magneto-electric elements are obtained in the electric transverse components and Green
tensor expressions, respectively. These new results can be considered as a generalisation form of the previously published work
