Electrical and Electronic Engineering, Engineering
12
Scopus Publications
Scopus Publications
Computational Study of the Impact of RF Breakdown Plasma on the Performance of Dual-Band Magnetically Insulated Line Oscillator Mohit Kumar Singh, Rajnish Kumar, Gowre Soumya, Manpuran Mahto IEEE Transactions on Plasma Science, 2026 The phenomenon of pulse shortening has a significant impact on the long-pulse operation of the magnetically insulated line oscillator (MILO). The radio frequency (RF) breakdown plasma formed on the surface of the slow wave structure (SWS) disks is widely regarded as the primary cause of pulse shortening in MILO. The degradation of metallic high-frequency structures due to RF breakdown significantly reduces power and pulse duration, limiting the advancement of high-power microwave (HPM) technology toward higher power levels and longer pulse regimes. Due to the complexity of the RF breakdown process, this work employs simulation-based analysis to qualitatively assess its effects on the performance of an axially partitioned dual-band MILO (DBMILO). In these simulations, simplified ion emission from disk surfaces was introduced to approximate the influence of RF breakdown plasma within the interaction structure. The model represents plasma effects through user-defined light and heavy ions without including self-consistent ionization or electron dynamics. The results indicate that the presence of light ions, particularly hydrogen, can perturb beam–wave interaction and reduce output power, indicating the potential significance of plasma effects on DBMILO performance.
Efficient terahertz radiation absorption using a graphene and InSb pixel-based metasurface absorber: design and simulation Mohit Kumar Singh, Govindam Sharma, Kamisetty Likhita Bhavani, G. Lalitha, M. Likhith Krishna Yadav, Subramaniam Rajasekaran Journal of the Optical Society of America B Optical Physics, 2025 Metasurfaces offer a fascinating approach for THz absorption applications due to their exceptional ability to manipulate electromagnetic wave properties. Our study involved simulating metasurface containing pixels made of graphene and InSb for the absorption of terahertz waves. The metasurface consisted of an array of pixelated meta-atoms on a dielectric substrate supported by a perfect electric conductor. Simulations were conducted using the well-explored commercially available software CST Microwave Studio Suite. A metasurface comprising six graphene, two InSb, and one unpatched meta-atom achieved a remarkable absorptance of 0.99 across a broad spectral regime of 1.5 THz spanning between 2.20 and 3.70 THz.
Simulation investigations of an efficient L-band bi-frequency MILO with ridged-disk-loaded interaction structure Mohit Kumar Singh, Manpuran Mahto, Pradip Kumar Jain Physics of Plasmas, 2024 This article presents simulation studies of an L-band bi-frequency magnetically insulated line oscillator for its efficiency enhancement using a ridged-disk-loaded radio frequency (RF) interaction structure. The electromagnetic (EM) properties of the RF interaction structure implemented with conventional and ridged disk have been investigated with the aid of CST microwave studio suite. A comparative study between the EM properties of conventional slow-wave structures and ridged-slow-wave structures (RSWS) is presented. The impact of adding ridges at the tip of disks has been examined for its influence on the dispersion curve, phase velocity, and coupling impedance. The coupling impedance of the RSWS with ridged-disk-loaded vanes was found to be greater than that of the conventional SWS. Furthermore, influence on output power of the device is observed for different ridge's parameters. With the optimum dimension of ridge parameters, particle-in-cell simulation detects an high-power microwave at frequencies of 1.20 and 1.40 GHz, producing 3.8 GW of cumulative peak RF power with a conversion efficiency of 23.8%, when operated with a 420 kV input DC voltage and current of 38 kA.
Design Study of a Metamaterial-Assisted Magnetically Insulated Line Oscillator Rajnish Kumar, Mohit Kumar Singh, Pradip Kumar Jain, Manpuran Mahto IEEE Transactions on Plasma Science, 2024 In this article, a magnetically insulated line oscillator (MILO) assimilated with metamaterial-based complementary electric split ring resonator (CeSRR) disks is studied to enrich the device efficiency. The beams absent (cold) studies have been accomplished to observe the impact of metamaterial-based CeSRR disks on the electromagnetic (EM) behavior of the MILO. CeSRR disk-loaded radio frequency (RF) interaction structure showed promising interaction impedance compared to the conventional one, improving overall device efficiency. The particle-in-cell (PIC) simulation studies are accomplished to investigate the mechanism of interaction between the electron beam and RF wave and to assure the three phases of operation of MILO as well as to evaluate the high-power enhancement of the proposed MILO. With the input specifications of 460 kV and 62 kA, PIC simulation predicted 10.1 GW of output power at 2.40-GHz frequency during the beam–wave interaction mechanism in the proposed MILO. The peak power conversion efficiency of the proposed MILO is ~35.41%, which is comparatively higher than the conventional MILO.
Simulation investigations of a pixelated metasurface absorber comprising CdTe, InAs, and InSb pixels for terahertz radiation Mohit Kumar Singh, V Chandana, P Nikitha, K Rakshitha 2024 Control Instrumentation System Conference Guiding Tomorrow Emerging Trends in Control Instrumentation and Systems Engineering Ciscon 2024, 2024 A metasurface was designed for significant absorption of normally incident terahertz radiation in the spectral range of 2 to 8 THz. This metasurface comprises metaatoms featuring InSb-patched, InAs – patched, CdTe – patched, and unpatched pixels, strategically arranged on the illuminated face of a gold – backed polyimide substrate. Extensive simulations using commercial software have determined that the proposed metasurface design achieves remarkable maximum absorptance of 0.99, with a minimum absorptance of 0.95, within the frequency bands of 0.30893 – 0.59178 THz. The tuning capabilities of the proposed metasurface are characterized by an average tuning rate of 1.1 THz per Tesla (THzT-1) and a substantial dynamic range of 0.882 THz when subjected to a controlling magnetostatic field aligned parallel to the incident electric field. The incorporation of InSb, CdTe, and InAs patches proves vastly superior to using patches of only one of these materials.
Investigation of Metasurface Absorber Using CdTe,Graphene and InSb for Terahertz Applications Nishant Sharan, Mohit Kumar Singh, Gundlapalli Mamatha, Naggalla Chandrika, Gujjapaneni Masthan Babu 2024 Control Instrumentation System Conference Guiding Tomorrow Emerging Trends in Control Instrumentation and Systems Engineering Ciscon 2024, 2024 This work analyzes the possibilities of graphene, indium antimonide (InSb), and cadmium telluride (CdTe) metasurface absorbers for terahertz (THz) applications. A possible method of regulating THz radiation, which is essential for many applications such as spectroscopy, imaging, and communication systems, is provided by metasurface absorbers. Because of their unique features, CdTe, InSb, and graphene are suitable options for metasurface absorbers in the THz range. High absorption coefficients and tunability are provided by CdTe, large THz absorption is shown by InSb, and ultra-wideband absorption and active modulation are offered by graphene. The results reveal important insights into the performance of the proposed metasurface absorbers in the range of 2-4 THz. The proposed metasurface’s optimum dimensions exhibits dual band effectiveness with absorptance exceeding 91%. The first band ranging between 2.59-2.70 THz displays absorptance 0.91 while the second band ranging between 2.83-2.96 THz shows the absorptance about 0.99 with an average tuning rate of 0.6 THz T−1.
Dual-Band Magnetically Insulated Line Oscillator Realized With Ridged-Disk-Loaded Vanes Mohit Kumar Singh, Pradip Kumar Jain, Manpuran Mahto IEEE Transactions on Electron Devices, 2023 In this article, a dual-band magnetically insulated line oscillator (DBMILO) incorporated with the ridged disk-loaded vanes rather than a conventional disk-loaded vane is examined to improve the interaction efficiency. Both, cold (beam absent) and hot (beam present) simulations have been carried out to examine the impact of ridged slow wave-structure (RSWS) on the performance of ridged DBMILO (RDBMILO). Cold simulations have been performed to investigate the impact of RSWS on the electromagnetic (EM) characteristics of the RDBMILO. The RF performance of the RDBMILO has been evaluated using the CST particle-in-cell (PIC) simulation. A collective peak RF power of 4.6 GW is obtained at 3.30 and 9.85 GHz frequencies. The peak power conversion efficiency of the RDBMILO was found to be <inline-formula> <tex-math notation="LaTeX">$\\sim $ </tex-math></inline-formula>16.4%. Compared to the conventional DBMILO (CDBMILO), an enhancement of <inline-formula> <tex-math notation="LaTeX">$\\sim $ </tex-math></inline-formula>28% in both RF power and efficiency is detected with the RDBMILO.
Metamaterial-Based Novel S-Band Coaxial Slow Wave Structure Rajnish Kumar, Mohit Kumar Singh, Manpuran Mahto, Pradip Kumar Jain IEEE Transactions on Electron Devices, 2023 In this article, a novel <inline-formula> <tex-math notation="LaTeX">${S}$ </tex-math></inline-formula>-band metamaterial-based coaxial slow wave structure (MCSWS) is proposed for high-power microwave (HPM) applications. The electromagnetic features of the proposed MCSWS and conventional coaxial slow wave structure (CCSWS) are investigated. The dispersion curve and coupling impedance of the two models have been compared to ascertain the advantages of MCSWS over CCSWS. For the same structural dimensions, the <inline-formula> <tex-math notation="LaTeX">$\\pi $ </tex-math></inline-formula> mode resonant frequency of the fundamental mode (TM00) of MCSWS is 2.49 GHz, whereas it is 3.82 GHz for the CCSWS. The coupling impedance of the MCSWS at its resonant frequency is <inline-formula> <tex-math notation="LaTeX">$\\sim 2000~\\Omega $ </tex-math></inline-formula>, while it is <inline-formula> <tex-math notation="LaTeX">$\\sim 115~\\Omega $ </tex-math></inline-formula> for the CCSWS. Furthermore, the transmission characteristics of the fabricated MCSWS have been measured with the help of Anritsu MS2037C VNA Master. The measured reflection coefficient confirms the operation of MCSWS at 2.48 GHz. Moreover, a magnetically insulated line oscillator (MILO) configured using the proposed MCSWS has been investigated in the presence of electron beams to predict its RF performance. The particle-in-cell simulation predicted an output power of 6 GW at a frequency of 2.4 GHz with a power conversion efficiency of 21%.
Efficiency Enhancement of a Dual-Band Magnetically Insulated Line Oscillator Using a Modulation Cavity Mohit Kumar Singh, Manpuran Mahto, Pradip Kumar Jain IEEE Transactions on Electron Devices, 2023 In this article, performance enhancement of a dual-band magnetically insulated line oscillator (DBMILO) using a modulation cavity has been presented. In the proposed design, a modulation cavity has been introduced in between the slow wave structure (SWS) of the output end, which lessens the energy spread of the modulated beam electrons. The impact of the modulation cavity on the transmission characteristics and the operating frequency of the modified DBMILO are investigated through electromagnetic (EM) simulation. The dimensions of the modulation cavity are optimized to ensure approximately the same operating frequency in the modified design. The RF behavior of the proposed and conventional design is examined through the particle-in-cell (PIC) solver code. For the input dc voltage and current of 500 kV and 56 kA, respectively, the output power of the conventional DBMILO provides ~3.6 GW with 12.8% efficiency, whereas the proposed DBMILO with modulation cavity generates ~4.8 GW with 17.1% efficiency. The microwave frequency in both cases is 3.4 and 10.1 GHz. Compared to the conventional DBMILO, the power efficiency of DBMILO with modulation cavity enhances by 33%.
