Design of single feed dual-band millimeter wave antenna for future 5G wireless applications

State of the art communication system pave way for microstrip patch antennas to experience rapid development. Nowadays, patch antennas are becoming increasingly popular due to their light weight and low profile making them easy to fabricate and integrate into the feeding network. This paper presented a single feed dual-band band antenna for 5G application operating in the 28 and 38 GHz millimeter wave band with an improved efficiency. The antenna is designed and simulated on Computer Simulation Technology (CST) platform using FR-4 substrate with 0. 8 mm height, 4.67 dielectric constant and 0.002 loss tangent. The total size of the antenna is 8 × 8 mm2, the rectangular radiator of the antenna is 3.4 × 3.4 mm2 in size, where an inverted-L is introduced into the radiator to achieve dual-band capability, The antenna is fed through 50 Ω feed line probe of about 2.3 × 0.4 mm2 in dimension. The results of the simulation shows that the antenna achieved wide bandwidth in the upper band (38 GHz) of about 3.54 GHz (35.56 GHz – 39.12 GHz) with over 6 dB gain and the lower band (28 GHz) produce a bandwidth of about 1430 MHz (27.27 GHz – 28.70 GHz) with 2.7 dB gain suitable for 5G application

Closed-Form 3-D Position Estimation Lateration Algorithm Reference Pair Selection Technique for a Multilateration System

The position estimation (PE) accuracy of the lateration algorithm of a multilateration system depends on several factors. These factors include the number of ground receiving station (GRS)s deployed, the approach to the lateration algorithm, the geometry of the deployed GRSs, the number of GRS used as reference for the lateration algorithm and the choice of GRS used as reference to generate the time difference of arrival (TDOA) measurements for the lateration algorithm. A closed-form reference pair lateration algorithm based on a total of five GRSs is developed and a technique for selecting the suitable GRS reference pair to generate the TDOA measurements to be used with lateration algorithm is suggested. The technique is based on condition number computation and selecting the GRS pair with the least condition number as a reference for the closed-form lateration algorithm. The suggested technique is validated using 5-square and pentagon GRS configurations at some selected aircraft positions. The validation results show that the suggested technique can be used to determine the suitable GRS reference pair to generate the TDOA measurements for a passive multilateration system

Closed-form 3-D position estimation lateration algorithm reference pair selection technique for a multilateration system

The position estimation (PE) accuracy of the lateration algorithm of a multilateration system depends on several factors. These factors include the number of ground receiving station (GRS)s deployed, the approach to the lateration algorithm, the geometry of the deployed GRSs, the number of GRS used as reference for the lateration algorithm and the choice of GRS used as reference to generate the time difference of arrival (TDOA) measurements for the lateration algorithm. A closed-form reference pair lateration algorithm based on a total of five GRSs is developed and a technique for selecting the suitable GRS reference pair to generate the TDOA measurements to be used with lateration algorithm is suggested. The technique is based on condition number computation and selecting the GRS pair with the least condition number as a reference for the closed-form lateration algorithm. The suggested technique is validated using 5-square and pentagon GRS configurations at some selected aircraft positions. The validation results show that the suggested technique can be used to determine the suitable GRS reference pair to generate the TDOA measurements for a passive multilateration system

Energy-aware message distribution algorithm for enhance FANET pipeline surveillance reliability

Features such as the communication scheme, energy awareness, and task distribution amongst others are the key component that characterizes the Flying Ad-hoc Network (FANET). The operational efficiency in FANET surveying a specific region is affected by the nature of the UAVs' node placement, routing protocol, energy-aware task distribution, and node interaction amongst others. In this paper, Drone 1 (D1), Master Drone (DM), and Drone 2 (D2) were used to survey a pipeline of length 12.2 m. This paper aims at minimising energy use by drones during surveillance using energy-aware node exchange technique, task interaction and distribution scheme for each UAV. Due to fast energy depletion of DM due to packets aggregation, its election is based on the UAV with the highest energy before take-off. For two different simulations, 14,697.0 J and 14,836.6 J were obtained for DM. To avoid system failure due to fast energy loss of DM, the drones swapped positions and status. First swapping command comes up when DM loses 50% of its energy, while the second command occurs when it further loses 15%. Return to base threshold energy is computed for the three UAVs to avoid crash due to insufficient energy during surveillance. DM returns to base threshold energy for both single and double swapping simulation were 658.105 J and 652.456 J respectively. From the results obtained the algorithms were able to exchange nodes to maximize energy usage and perform an interaction-based task distribution for cooperative task sharing during surveillance. This translates into longer surveillance time and effective telemetry data aggregation

Quantitative datasets reveal marked gender disparities in Earth Sciences faculty rank in Africa

As in most disciplines of science, technology, engineering, mathematics and medicine (STEMM), gender disparity is prevalent in the ranking of Earth Sciences faculties at senior and advanced levels. (i.e., Associate and Full Professors). In this study, a robust database was mined, created, and analyzed to assess the faculty compositions of 142 Earth Science departments in 39 countries across Africa. The data were collected from verifiable online resources focusing on ranks and gender ratios within each department. The studied earth science departments cut across universities in northern, southern, central, eastern, and western Africa. Our data revealed that female faculty members are predominantly underrepresented in most of the departments documented and are markedly uncommon in senior positions such as Professors, associate Professors, and senior researchers compared to their male counterparts. On the contrary, female faculty members are predominant in the lower cadres, such as lecturers, teaching, and graduate assistants. The observed male to female ratio is 4:1. At the base of this gender gap is the lower enrolment of female students in Earth Science courses from undergraudate to graduate studies. To achieve gender equality in Earth Science faculty composition in Africa, we recommend increasing female students’ enrollment, mentoring, awareness, timely promotion of accomplished female researchers, and formulation of enabling government policies. More work-related policies that guarantee work-life balance for female earth science academic professionals should be formulated to attract and retain more women into Earth Sciences careers