The Impact of Substrate Materials to the Design of UWB Modern Antennas

The theory of microstrip antennas has motivated us to design a highly improved gain antenna under this category. It is a microstrip monopole antenna characterized by omni-directional radiation as well as a high radiation gain. A review of different methodologies to designing antennas with broad/ultra-wide band performance for various applications is enriched by our original antenna design. This is an original model analyzed over different substrate materials and finally optimized for the bandwidth of (3.3 - 5.8) GHz just below ?10 dB of return loss (RL). The antenna is judged for high gain when the ground plane size is reduced to nearly half that of substrate. The impact of the substrate materials is discussed in this article. The master design tool is Ansoft High Frequency Simulator Structure (HFSS), one of Finite Element Method (FEM) based software tools. The antenna would be printed on a 1.524 mm thick Rogers (RO3003C) substrate;overall size of 33.4 × 33.4 squared millimeters. At the optimal resonance frequency of 3.8 GHz, simulation results perfectly agree with the standards of UWB antennas, with a high radiation gain and impedance matching status.

Design and Realization of a Dual Wide Band Printed Monopole Antenna for WiFi and WiMAX Systems

A Printed monopole antenna was designed and manufactured with the wideband performances in two frequency bands. The antenna is compatible with WiMAX and WiFi standards. After reviewing a couple of literatures, the antenna was designed, analyzed and proven for two central frequencies, 2.5 GHz and 5.6 GHz, with much improved bandwidths. Finally, the antenna was manufactured with the overall size of 4 cm × 4.4 cm on Rogers (RO4003) substrate. The antenna is made into three L-shaped radiators. A 50 Ω microstrip feed line connects the port to the two L-shaped radiators of different lengths, thus providing two frequency bands. An inverted L-shaped radiator is printed on the less radiation upped side, to tune the antenna for wide band performances. The raised problem was solved with the integral equation solver of the Ansoft high frequency simulator structure (HFSS-IE). Optimal results are presented in this article: the simulation results in comparison with measured results. This antenna prototype’s overall dimensions would be readjusted according to any industrial and manufacturing requests.

Design of an 868 MHz Printed S-Shape Monopole Antenna

The purpose of this work is to design and analyze an s-shaped printed circuit board (PCB) monopole antenna. The antenna was analyzed to operate at a resonance frequency band of 868 MHz;acceptable in 915 MHz as well. The s-shape is selected due to the need of reducing the overall size of the normal monopole antenna. The printed antenna was designed with an approximate overall size of 39 × 56 mm2 of which the antenna’s upper side is 26 × 39 mm2 while its reference ground board was sized at 39 × 30 mm2. The antenna is fed by a strip line of 3 × 1.5 mm2, in series with a 4.4 pF capacitance and shunt with an 8.7 nH inductance for purpose of antenna’s impedance matching with the input. A couple of existing publications showed that PCB antenna is not a new technology;however not an old technology for telecommunication industry. The raised problem by this work was duly solved with HFSS as a tool;excellent results are presented. After duly matching the antenna’s impedance with 50 Ω microstrip feed-line, solutions for overall performance were analyzed and demonstrated optimal: radiation patterns were proven omnidirectional, antenna gain optimized. The present antenna prototype’s overall dimensions can be readjusted according to any industrial and manufacturing requests.

The Influence of Dust and Black Carbon on Clouds, in Africa

The aerosol can change the clouds properties;the clouds, however, affect the normal behavior of aerosol optical depth. Considerable effects arise while the interaction of aerosol and clouds unavoidably encounters the presence of greenhouse gases (GHGs) in atmosphere. This research discusses the influence of two selected aerosol types, on the clouds in Africa, over the selected sub-time series in the years 1980-2018. Sahara desert’s dust is mainly constituted by hematite minerals;which, in return, is mainly composed by the iron oxides, a powerful solar and infra-red radiation absorbing matter and thus a strong and direct radiative forcing agent. For that reason, together with the fact that it is windblown over the biggest region that surrounds the desert, dust is one of the strongly considered aerosol in this research. Besides, black carbon (BC), mostly from the anthropogenic biomass burning process in the mid latitude’s African savanna, is the second aerosol type selected for this research: it is one of the abundantly available aerosol types and it is one of the strongest atmospheric radiant energy absorbers. For sake of valid and trustworthy results, the data is collected from multiple satellite remote sensing tools and instruments, all targeting the aerosol-cloud interaction and effects. In this research, different measurements were carried out;those are the spatiotemporal averaged cloud cover, the aerosol (dust and BC) extinction optical thickness (AOT), the anomaly of aerosol optical depth (AAOD) as well as different scatter plots’ correlation analysis. For findings: the direct influence of hydrophilic BC on clouds formation in central African sub-region is experimentally demonstrated;the dust aerosol highly influences the North African sub-region’s cloud formation.