Indonesian Journal of Electrical Engineering and Informatics (IJEEI)
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3D printed horn antenna using direct metal laser melting technique for millimetre wave applications
A 3D printed horn antenna at ka-band is presented in this paper. The horn antenna is well known for high gain performance. The performance of the horn antenna manufactured using 3D printed technology is investigated in this work. The horn is designed based on WR-28 waveguide standard. The proposed horn is simulated by computer simulation technology (CST) software and fabricated using 3D printing direct metal laser melting technique. The 3D printing technique gives the antenna an advantage of being not just rapid manufactured but also low-cost and lightweight. However, several works reported on 3D printed devices highlight the effects of surface roughness and dimensional tolerance on the performances. Therefore, the printed horn is profiled to correlate the surface roughness and dimension tolerance towards the performance. The printed horn is measured using standard VNA. The results showed that the measured performance agreed fairly with the simulation with directive radiation pattern at 15 dBi gain. The printed horn has a weight of less than 130g and considerably working at Ka band regardless of the surface roughness resulted from the fabrication process
Floral structure for textile-based metamaterial absorber
Based on an annulled circle structure metamaterial absorber (MMAb), a floral structure MMAb design is proposed for performance improvement especially on absorptivity. Since the initial purpose of designing the MMAb is for hiding one’s existence from electromagnetic motion detector, it is expected that the MMAb will has flexibility as one of its characteristics. The MMAb composes of textile-based substrate in between floral structure at the top and ground plane at the bottom, based on metallic plate. The targeted center frequency is 10.525 GHz and through series of simulation done in CST Microwave Software, the MMAb can reach up to 97.03% of absorptivity. The operating angle can be extended at least 68o before its absorptivity deteriorated below 80%. In addition, the proposed MMAb has a high absorptivity regardless of the polarization angle of the electromagnetic waves
Design and Performance Analysis of 250 kW Grid-Connected Photovoltaic System in Iraqi Environment Using PVsyst Software
A 250 kW grid-connected photovoltaic (PV) plant systems have been installed at the Ministry of Electricity in Baghdad and penetrated to the Iraqi national grid since November 2017. This is the first high power grid-connected PV system that has been installed in Iraq and it’s one of the four parts 1MW large-scale PV systems that should be completed in early of 2019. This paper presents the design and performance analysis of this system using a PVsyst software package. The performance ratio and different losses that occurred in the system are also calculated. The results show that the performance ratio is 75% using 1428 photovoltaic panels type (Sharp 175Wp) spread over an area of 1858 m². The total energy injected into the grid is (346692 kWh/year) .Based on the simulation results that developed in this paper, the practical PV grid-tied system has been implemented in Baghdad site
Game theory based Ad-hoc On Demand Distance Vector Routing Protocol to Extend the Wireless Sensor Networks Life Time
This paper proposes a solution to increase the energy life time of wireless sensor networks (WSNs) via a concept of game theory enabled ad-hoc on demand distance vector (AODV) routing algorithm. Game theory is an optimal promising candidate for decision making in a wireless networking scenario to find the optimal path for data packets transfer between source node and destination node, where combination with the AODV routing algorithm, a procedure of game theory enabled AODV (GTEAODV) is developed and proposed in this research paper. The developed and proposed methodology is validated through simulation in NS2 environment and the results show an improvement in energy life time of the order of 30-35% in comparison to the existing routing methodology which uses co-operative routing techniques among the nodes in WSN. Further, the throughput of game theory enabled adhoc on demand routing is also highly improved in comparison to existing traditional approaches though obtained results. Though, game theory approach is an existing approach concatenation of it with AODV can provide increased network performance which is significant as portrayed in research results shown in the paper. Hence, by virtue of providing enhanced energy life time and data security through the nature of the algorithm, the proposed GTEAODV algorithm can be employed in defence applications for secure data transmission and reception for forthcoming deployment of 5G systems which are blossoming in world wide scenario
A New Small Dual-Band Elliptical Microstrip Antenna for Ku/K Band Satellite Applications
In this paper a new design of a dual small band small elliptical microstrip antenna is proposed for Ku and K band satellite applications. The basic antenna structure is an elliptical patch with inset-feed, which is modified by adding two rectangular slots in the radiation patch. The proposed antenna has been designed and fabricated on 1.58 mm thick FR4 substrate whose dielectric constant is 4.4, with dimensions of about 10×12×1.58 mm³. The antenna structure was validated using two different electromagnetic solvers and by measuring the results using a Vector Network Analyzer (VNA). The measured and simulated results show two resonant frequencies that define two bandwidths. Moreover, the proposed antenna frequency bands and the consistent and symmetrical radiation patterns make it an appropriate candidate for many applications such as the Ku/K band satellite application and wireless communications
Control design of a de-weighting upper-limb exoskeleton: extended-based fuzzy
One of the most common issues to human is fatigue. A technology known as exoskeleton has been identified as one of the solutions to address this issue. However, there are two issues that need to be solved. One of them is the control approach. Hence, the main aim of this work, is to investigate the control design for upper-limb exoskeleton. An extended based fuzzy control is proposed to observe the effectiveness of the exoskeleton in dealing with human with different strength. Three conditions of human strength were applied. PID was used for a comparison purpose. It is shown that with the proposed control approach, the exoskeleton can assist human to achieve the desired trajectory accurately with a minimal amount of torque required
A Bridge between Legacy Wireless Communication Systems and Internet of Things
The software-defined radio (SDR) is a flexible platform that can adapt to various wireless telecommunication frequencies. It is able to provide a reconfigurable communication infrastructure for wireless systems. Hence, SDR is proposed here as a bridge between legacy wireless communication systems and the Internet of Things (IoT) via standard telecommunication protocols. The standard protocols are hypertext transfer protocol (HTTP), simple mail transfer protocol (SMTP), and message queuing telemetry transport (MQTT). Data collected from legacy wireless systems have been formatted via JavaScript object notation (JSON) for interoperability and categorized according to the application and the communication pattern. The extracted data are then transferred over MQTT for machine-to-machine (M2M) communication, over SMTP for machine-to-human (M2H) notification, and over HTTP for human-to-machine (H2M) communication. However, received audio signals from FM-based broadcasting stations have been transferred to the Internet servers over extensible messaging and presence protocol (XMPP), in live audio streaming. The objective is to introduce an SDR-IoT bridge that is inexpensive, scalable, and interoperable. The analyses show that the environment has good-performance, and can be used for many applications of smart city sectors, for Internet Radio, and for Internet-based monitoring of airplanes and vessel navigation
Influence of single vacancy defect at varying length on electronic properties of zigzag graphene nanoribbons
Graphene, identified in 2004, is now an established two-dimensional (2D) material due to its outstanding physical and electronic characteristics namely its superior electrical conductivity. Graphene is a zero-gap material that has linear dispersion with electron-hole symmetry. As pristine sheet, it cannot be utilized in digital logic application without the induction of a band gap inside the band structure. In our work, the modeling and simulation of graphene nanoribbons (GNRs) are carried out to determine its electronics properties that are benchmarked with other published simulation data. A 4-Zigzag GNRs (4-ZGNRs) under different length are utilized. A single vacancy defects is introduced at various positions inside the atomic structure. The theoretical model is implemented based on single-neighbour tight binding technique coupled with a non-equilibrium Green’s function formalism. The single vacancy defects are represented by the elimination of tight binding energies in the Hamiltonian matrix. Subsequently, these matrix elements are utilized to compute dispersion relation and density of states (DOS) through Green’s function. It is found that single vacancy defects at different positions in 4-ZGNRs’ atomic structure under varying length has no significant impacts on the sub-band structure but these vacancies impact the DOS that are computed throught Green’s function approach
Analysis of coupled and decoupled PWM techniques for induction motor drive
Dual inverter fed induction motor drive-in open-end winding gives more advantages than multilevel inverter fed induction motor drives. For better quality of output voltage with low common mode voltage (CMV), in this paper analysis of coupled and decoupled PWM techniques for open end winding induction motor are carried. The analysis is carried in MATLAB/simulink environment for vector controlled open end winding induction motor drive. The performance of drive and PWM techniques are evaluated both in transient, steady state and loaded conditions
A new design of photonic transmitter for terahertz spectroscopy and imaging applications
In this paper we present the Design of Continuous Wave Terahertz photonic transmitter based on photodetector, THz antenna, and low-pass filter (LPF) and Direct Current “DC” Probe Bias. Before validating the whole system, we processed firstly with the optimization of the antenna which is responsible of the transmitting the RF signal providing from the photodetector then we have conducted a study on the design of a low pass filter “LPF” whose role is to block the received RF signal to reach the DC probe. After the optimisation of the proposed LPF, we have integrated the different components mounted on multi-layers GaAs substrate and simulated the final photonic transmitter by using an EM solver “Momentum” integrated in ADS “Advanced Design System”. The dimensions of the whole circuit are .The simulation results permit to validate the final circuit at 1.6 THz, the proposed photonic transmitter is suitable for terahertz spectroscopy and imaging applications