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Showing 2 results for Asari
Back Flashover Voltage on Transmission Tower of 275 KV Extra High Voltage Line (Case Study: Galang-Binjai)
Surya Hardi, Ferry R. A. Bukit, Irfan Nofri, Riza R. Wirasari, Muhd Hafizi Idris, Muzamir Isa,
Volume 21, Issue 2 (Special Issue on the 1st International Conference on ELECRiS 2024 Malaysia - June 2025)
Abstract
Overvoltage at the insulator terminal caused by a lightning strike can occur in two ways, i.e., a direct lightning strike on the phase line and ground wire. The insulator can be exposed to the phenomenon of back flashover (BFO) if the terminal voltage of the insulator is higher than its insulator critical voltage The lightning current characteristics are distinguished by the maximum current and the steepness. Differences in the characteristics in this study are identified as International Electrical Commission (IEC) and Conseil International des Grands Reseaux Electriques (CIGRE) impulse waveform standards. The footing-tower grounding system comes in different configurations, such as horizontal, vertical, and grid. Alternative transient program (ATP) software was used for simulating lightning strikes on ground wire and phase lines. The results exhibit that the highest critical voltage of the insulators on the footing tower through grid grounding when the surge current strikes ground wire (3308kV – 3395 kV), with the magnitude of the lightning current ranging from (48 kA – 3395 kA). For lightning direct stroke on the phase line, the critical voltage on vertical grounding is highest on (2938 kV -3021 kV).  The surge current flow footing-tower is highest on the grid. The currents magnitude flow in footing tower were influenced by impedance of grounding.
Open EMS Based Design of a CSRR Bandpass Filter for 5G: An Accessible Simulation Approach
Gauravkumar Asari,
Volume 22, Issue 3 (September 2026)
Abstract
Bandpass filters (BPFs) are critical components in 5G radio-frequency front-end systems, where wide bandwidth, low insertion loss, and compact size are simultaneously required. In this paper, a metamaterial-inspired wideband BPF based on Complementary Split Ring Resonators (CSRRs) loaded with a dumbbell-shaped Defected Ground Structure (DGS) is proposed for mid-band 5G applications centered at 4.7 GHz. Unlike conventional designs that rely on commercial electromagnetic solvers, the proposed filter is developed and analyzed using a fully open-source electromagnetic simulation framework based on Open EMS, enabling cost-effectiveness and design reproducibility. The design evolution from a single-ring CSRR to a triple-ring configuration is systematically presented to enhance magnetic coupling and bandwidth. The incorporation of a dumbbell-shaped DGS further modifies the ground current distribution, leading to improved selectivity and reduced insertion loss. The optimized filter achieves a fractional bandwidth of approximately 43%, a minimum insertion loss of 0.72 dB, and a return loss better than -35 dB using a low-cost FR-4 substrate. Comprehensive parametric analysis, metamaterial characterization, group delay response, and electromagnetic field distribution are provided to validate the proposed approach. The results demonstrate that the open-source Open EMS-based methodology can achieve performance comparable to commercial solvers, offering an accessible and reliable design pathway for next-generation microwave filter development.
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Creative Commons License
© 2022 by the authors. Licensee IUST, Tehran, Iran. This is an open access journal distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) license.