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A high efficiency on‐chip reconfigurable Doherty power amplifier for LTE communication cells
Kumar, Rajesh,Kanuajia, Binod Kumar,Dwari, Santanu,Kumar, Sandeep,song, Hanjung John Wiley Sons, Inc. 2018 MICROWAVE AND OPTICAL TECHNOLOGY LETTERS Vol.60 No.10
<P><B>Abstract</B></P><P>In this paper, a high efficiency on‐chip reconfigurable Doherty power amplifier (DPA) with proposed topology is proposed for LTE or 4G communication cells. The proposed DPA consists of input driver topology, hybrid coupler, asymmetric amplifiers, and 1:1 balun filtered network. The proposed input driver circuit provides wide amplified signal operation within range of 2.3GHz to 6GHz with flat gain of 33 dB. The amplified signal is unsteadily divided into two paths toward the carrier and the power amplifier by 90<SUP>0</SUP> hybrid couplers and demonstrates 27.6 dB and 28.3 dB of gain along with 83.2% and 84.5% of power added efficiency at average output power of 40 dBm. The high efficiency and almost flatness in gain stability of proposed DPA providing better solution in order to overcome the interference and the broadband issues for LTE communication cells. The balun‐filtered network is employed for combined the two outputs of carrier and peak amplifiers that provides more uniform desired band of operation in the frequency responses. The proposed DPA circuit are implemented and optimized by using advanced design RF simulator platform. The fabricated chip is made by using 0.13 μm GaN HEMT on Si‐Nitride monolithic microwave integrated circuit die process. The fabricated chip of DPA provides 85% of PAE with 28 dB gain which are made close agreement with simulation results. The size of chip is 2.8*1.2mm<SUP>2</SUP> which occupies less die area as compared to existing DPAs.</P>
Parametric resonance of composite skew plate under non-uniform in-plane loading
Rajesh Kumar,Abhinav Kumar,Sarat Kumar Panda 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.55 No.2
Parametric resonance of shear deformable composite skew plates subjected to non-uniform (parabolic) and linearly varying periodic edge loading is studied for different boundary conditions. The skew plate structural model is based on higher order shear deformation theory (HSDT), which accurately predicts the numerical results for thick skew plate. The total energy functional is derived for the skew plates from total potential energy and kinetic energy of the plate. The strain energy which is the part of total potential energy contains membrane energy, bending energy, additional bending energy due to additional change in curvature and shear energy due to shear deformation, respectively. The total energy functional is solved using Rayleigh-Ritz method in conjunction with boundary characteristics orthonormal polynomials (BCOPs) functions. The orthonormal polynomials are generated for unit square domain using Gram- Schmidt orthogonalization process. Bolotin method is followed to obtain the boundaries of parametric resonance region with higher order approximation. These boundaries are traced by the periodic solution of Mathieu-Hill equations with period T and 2T. Effect of various parameters like skew angle, span-tothickness ratio, aspect ratio, boundary conditions, static load factor on parametric resonance of skew plate have been investigated. The investigation also includes influence of different types of linearly varying loading and parabolically varying bi-axial loading.
Investigation of Ionic Transport Through Track-Etched Conical Nanopores of PET Membrane
Sushil Kumar,Rajesh Kumar,Sushil Kumar,Narinder Kumar,S. K. Chakarvarti 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.1
The control of ionic transportation inside the multi asymmetric conical nanopores in polyethylene terephthalate (PET) membrane was investigated. The conical nanopores were prepared by chemical etching in irradiated PET foil using etchant (9 M NaOH) and stopping solution (1 M NaCl + 1 M HCOOH). The behavior of ionic current was recorded under stepping voltage - 2 V to +2 V at different molar concentrations of potassium halides (KCl, KBr and KI) under symmetric bathing condition in electrochemical cell. It is found that the presence of multiple ionic species and the occurrence of counterion condensation of charge regulated polyelectrolyte play an effective role in ionic current rectification (ICR). The electrical conductance of conical nanopores may be estimated by measuring the ionic current rectification properties of track-etched nanopores. The charge transport properties vary with molar concentration and pH of electrolyte. Moreover, ICR may be used as a voltage gating phenomena with wide technological applications.
Heat Flux Measurements in High Velocity Oxygen-Fuel Torch Flow for Testing High Thermal Materials
Rajesh Kumar Chinnaraj,Seong Man Choi(최성만),Seong Min Hong(홍성민) 한국추진공학회 2020 한국추진공학회 학술대회논문집 Vol.2020 No.7
고열 재료를 시험평가 하기 위한 HVOF 흐름에서 가든 게이지(Gardon gauge)를 이용하여 열유속을 측정하였다. 노즐 출구로부터 4 개의 다른 위치에서 열유속 측정을 수행하였다. 실험 중 가든 게이지를 수냉시켰다. 유효한 가정을 적용하여 열량 열유속(Calorimetric heat flux)을 계산하고 가든 게이지의 열유속 측정 결과와 잘 일치하는 것으로 나타났으며, 따라서 서로를 검증했습니다. A Gardon gauge was used to measure heat fluxes in a HVOF flow intended for testing high thermal materials. The measurements were taken at four different locations from the nozzle exit. The Gardon gauge was water cooled during the experiments. Applying valid assumptions, the calorimetric heat fluxes were calculated and were shown to be in good agreement with Gardon gauge heat flux results, thus validating each other.
Molecular fossils “pseudogenes” as functional signature in biological system
Rajesh Kumar Singh,Divya Singh,Arpana Yadava,Akhileshwar Kumar Srivastava 한국유전학회 2020 Genes & Genomics Vol.42 No.6
Pseudogenes have been known as non-functional molecular relics developed from inactivated genomic mutations while evolution. However, they have a various function at distinct molecular stages (DNA, RNA and protein) in different biological events including in cancer and associated with parental-gene-dependently and parental-gene independently. The interactions of pseudogenes with ancestor genes or other genes alter in their sequences and transcriptional processes. Pseudogene of RNA sequences have multiple functions in post-transcriptional activities as antisense RNAs, endogenous small-interference RNAs, and competing endogenous RNAs. Moreover, it also plays vital roles in controlling of its parent genes and other pseudogenes transcribing into RNA. Pseudogene transcripts make small interfering RNA or decline cellular miRNA level. The current review focuses on pseudogene functional signature in human genome by regulating the gene expression.
Implementation of 12T and 14T SRAM Bitcell Using FinFET with Optimized Parameters
Rajesh Kumar Raushan,Mohammad Rashid Ansari,Usha Chauhan,Muhammad Khalid,Baibaswata Mohapatra 한국전기전자재료학회 2021 Transactions on Electrical and Electronic Material Vol.22 No.3
In this paper, we have implemented 12T and 14T SRAM bitcell using FinFET with optimized parameters. Optimized parameters are related in terms average power consumption, delay, power delay product (PDP), and energy delay product (EDP). Simulation results of all parameters of 12T and 14T SRAM bitcell are reported with 22 nm FinFET technology. All parameters of 12T and 14T SRAM using FinFET are compared to conventional 12T and 14T SRAM and found that the results have improved in average power consumption, PDP, EDP, and propagation delay. Parameters for 12T SRAM using FinFET includes average power consumption, propagation delay, PDP and EDP, which are improved by 99%, 79.2%, 99.7% and 99.7%, respectively. Similarly, designing 14T SRAM using FinFET, gets improvements of 99% in Average Power consumption, 76.5% in propagation Delay, 99.4% in PDP, and 99.5% in EDP.
Application and Environmental Risks of Livestock Manure
Kumar, Ramasamy Rajesh,Park, Bong Ju,Cho, Jae Young The Korean Society for Applied Biological Chemistr 2013 Applied Biological Chemistry (Appl Biol Chem) Vol.56 No.6
Over the past few decades, livestock production has undergone an industrial revolution, resulting in the large-scale generation of livestock manure. Livestock manure has many beneficial nutrients, which can improve agricultural crop production, and is an organic alternative to chemical fertilizers. Livestock manure requires proper treatment before application to agricultural land, because it contains toxic heavy metals and pathogenic microorganisms. When improperly treated, stored or used, livestock manure can pollute rivers, soil ecosystems, and underground drinking water, thereby affecting all living organisms nearby. In this article, we illustrate the land applications and environmental risks associated with the use of livestock manure.
Fate, Occurrence, and Toxicity of Veterinary Antibiotics in Environment
Kumar, Ramasamy Rajesh,Lee, Jae Taek,Cho, Jae Young The Korean Society for Applied Biological Chemistr 2012 Applied Biological Chemistry (Appl Biol Chem) Vol.55 No.6
The increasing worldwide usages of Veterinary Antibiotics (VAs) for therapeutic and nontherapeutic are becoming serious issue due to its adverse effects on all living organisms. Release of VAs into the aquatic and terrestrial environments results in antibiotic resistance in bacteria and toxicity to humans, animals, and plants. This review covers the present scenario on VA usage, occurrence, toxicity, and removal techniques.
Rajesh Kumar Chinnaraj,장현식(Hyeon Sik Jang),오필용(Phil Yong Oh),홍성민(Seong Min Hong),최성만(Seong Man Choi) 한국연소학회 2020 한국연소학회지 Vol.25 No.1
Need to improve the performances of the gas turbines and rocket engines are hindered by the limitations caused by melting points of the metallic super alloys at the combustor outlet nozzle or turbine components. High thermal resistive non-metallic materials are considered as future solutions to this problem. Most of these alternative non-metallic materials are carbon based composite materials and these materials can enable the gas turbines or rocket engines to operate at temperatures higher than the metallic super alloys. In this paper, a hydrocarbon fuel based evaluation system for carbon based composite materials is introduced. This evaluation system allows the testing and validation of the material specimens in a fuel burnt high thermal flow. The local Mach numbers were measured at five different locations using wedge probes in the flow’s axial direction. The results reveal that the measured Mach numbers were almost constant about 1.4. The Mach number results indicate the flow generated by the evaluation system was stable and suitable for material evaluation.