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Potentiality of semiconducting diamond as the base material of millimeter-wave and terahertz IMPATT devices

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Journal of Semiconductors 2014年第3期35卷 39-49页

作者： aritra acharyya Suranjana Banerjee J.P.Banerjee Institute of Radio Physics and Electronics University of Calcutta Academy of Technology West Bengal University of Technology

An attempt is made in this paper to explore the potentiality of semiconducting type-IIb diamond as the base material of double-drift region（DDR） impact avalanche transit time（IMPATT） devices operating at both millimetre-wave（mm-wave） and terahertz（THz） frequencies. A rigorous large-signal（L-S） simulation based on the non-sinusoidal voltage excitation（NSVE） model developed earlier by the authors is used in this study. At first,a simulation study based on avalanche response time reveals that the upper cut-off frequency for DDR diamond IMPATTs is 1.5 THz, while the same for conventional DDR Si IMPATTs is much smaller, i.e. 0.5 THz. The L-S simulationresultsshowthattheDDRdiamondIMPATTdevicedeliversapeakRFpowerof7.79Wwithan18.17%conversion efficiency at 94 GHz; while at 1.5 THz, the peak power output and conversion efficiency decrease to6.19mWand8.17%respectively,taking50%*** diamond and Si shows that the former excels over the later as regards high frequency and high power performance at both mm-wave and THz frequency bands. The effect of band to band tunneling on the L-S properties of DDR diamond and Si IMPATTs has also been studied at different mm-wave and THz frequencies.

关键词： diamond IMPATTs DDR large-signal simulation millimeter-wave terahertz

Effect of junction temperature on the large-signal properties of a 94 GHz silicon based double-drift region impact avalanche transit time device

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Journal of Semiconductors 2013年第2期34卷 19-30页

作者： aritra acharyya Suranjana Banerjee J.P.Banerjee Institute of Radio Physics and Electronics University of Calcutta92APC RoadKolkata-700009India Academy of Technology West Bengal University of TechnologyAdisaptagramHooghly-712121West BengalIndia

The authors have developed a large-signal simulation technique extending an in-house small-signal simulation code for analyzing a 94 GHz double-drift region impact avalanche transit time device based on silicon with a non-sinusoidal voltage excitation and studied the effect of junction temperature between 300 and 550 K on the large-signal characteristics of the device for both continuous wave （CW） and pulsed modes of operation. Results show that the large-signal RF power output of the device in both CW and pulsed modes increases with the increase of voltage modulation factor up to 60%, but decreases sharply with further increase of voltage modulation factor for a particular junction temperature; while the same parameter increases with the increase of junction temperature for a particular voltage modulation factor. Heat sinks made of copper and type-IIA diamond are designed to carry out the steady-state and transient thermal analysis of the device operating in CW and pulsed modes respectively. Authors have adopted Olson＇s method to carry out the transient analysis of the device, which clearly establishes the superiority of type-IIA diamond over copper as the heat sink material of the device from the standpoint of the undesirable effect of frequency chirping due to thermal transients in the pulsed mode.

关键词： admittance characteristics chirp bandwidth frequency chirping junction temperature large-signal analysis transient thermal analysis

Influence of self-heating on the millimeter-wave and terahertz performance of MBE grown silicon IMPATT diodes

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Journal of Semiconductors 2020年第3期41卷 13-22页

作者： S.J.Mukhopadhyay Prajukta Mukherjee aritra acharyya Monojit Mitra Department of Electronics and Telecommunication Engineering Indian Institute of Engineering Science and TechnologyWest Bengal–711103India Department of Electrical Engineering Cooch Behar Government Engineering CollegeWest Bengal–736170India Department of Electronics and Communication Engineering Cooch Behar Government Engineering CollegeWest Bengal–736170India

The influence of self-heating on the millimeter-wave(mm-wave)and terahertz(THz)performance of double-drift region(DDR)impact avalanche transit time(IMPATT)sources based on silicon(Si)has been investigated in this *** dependences of static and large-signal parameters on junction temperature are estimated using a non-sinusoidal voltage excited(NSVE)large-signal simulation technique developed by the authors,which is based on the quantum-corrected drift-diffusion(QCDD)*** variations of static parameters and non-linear variations of large-signal parameters with temperature have been *** expressions representing the temperature dependences of static and large-signal parameters of the diodes are developed using linear and 2nd degree polynomial curve fitting techniques,which will be highly useful for optimizing the thermal design of the ***,the simulated results are found to be in close agreement with the experimentally measured data.

关键词： IMPATT oscillators linear temperature coefficient self-heating thermal runway quadratic temperature coefficient

Large-signal characterization of DDR silicon IMPATTs operating in millimeter-wave and terahertz regime

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Journal of Semiconductors 2013年第10期34卷 46-53页

作者： aritra acharyya Jit Chakraborty Kausik Das Subir Datta Pritam De Suranjana Banerjee J.P.Banerjee Institute of Radio Physics and Electronics University of Calcutta92APC RoadKolkata 700009India Supreme Knowledge Foundation Group of Institutions Sir J.C.Bose School of Engineering1Khan RoadMankunduHooghlyWest Bengal 712139India Academy of Technology West Bengal University of TechnologyAdisaptagramHooghly 712121West BengalIndia

The authors have carried out the large-signal characterization ofsilicon-based double-drift region （DDR） impact avalanche transit time （IMPATT） devices designed to operate up to 0.5 THz using a large-signal simulation method developed by the authors based on non-sinusoidal voltage excitation. The effect of band-to-band tunneling as well as parasitic series resistance on the large-signal properties of DDR Si IMPATTs have also been studied at different mm-wave and THz frequencies. Large-signal simulation results show that DDR Si IMPATT is capable of delivering peak RF power of 633.69 mW with 7.95% conversion efficiency at 94 GHz for 50% voltage modulation, whereas peak RF power output and efficiency fall to 81.08 mW and 2.01% respectively at 0.5 THz for same voltage modulation. The simulation results are compared with the experimental results and are found to be in close agreement.

关键词： band to band tunneling DDR silicon IMPATTs large-signal simulation millimeter-wave series resistance terahertz regime

Large-signal characterizations of DDR IMPATT devices based on group Ⅲ–Ⅴ semiconductors at millimeter-wave and terahertz frequencies

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Journal of Semiconductors 2014年第8期35卷 69-78页

作者： aritra acharyya Aliva Mallik Debopriya Banerjee Suman Ganguli Arindam Das Sudeepto Dasgupta J.P.Banerjee Institute of Radio Physics and Electronics University of Calcutta 92 APC Road Kolkata 700009 India Supreme Knowledge Foundation Group of Institutions Mankundu Hooghly West Bengal 712139 India

Large-signal （L-S） characterizations of double-drift region （DDR） impact avalanche transit time （IM- PATT） devices based on group III-V semiconductors such as wurtzite （Wz） GaN, GaAs and InP have been carried out at both millimeter-wave （mm-wave） and terahertz （THz） frequency bands. A L-S simulation technique based on a non-sinusoidal voltage excitation （NSVE） model developed by the authors has been used to obtain the high frequency properties of the above mentioned devices. The effect of band-to-band tunneling on the L-S properties of the device at different mm-wave and THz frequencies are also investigated. Similar studies are also carried out for DDR IMPATTs based on the most popular semiconductor material, i.e. Si, for the sake of comparison. A compara- tive study of the devices based on conventional semiconductor materials （i.e. GaAs, InP and Si） with those based on Wz-GaN shows significantly better performance capabilities of the latter at both mm-wave and THz frequencies.

关键词： DDR IMPATTs GaN group Ⅲ-Ⅴ large-signal simulation millimeter-wave terahertz regime wurtzite

Phytochemical Screening and Evaluation of Pharmacological Potential of Baliospermum solanifolium Leaf Extract

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Clinical Complementary Medicine and Pharmacology 2024年第1期4卷 69-75页

作者： Amit Mazumder Rabindra Nath acharyya Milton Kumar Kundu Pritam Kundu Md.Amirul Islam Md.Mustafizur Rahman Pharmacy Discipline Khulna UniversityKhulna-9208Bangladesh

Background:Baliospermum solanifolium is a traditional medicinal plant,locally known as“dantigaacha”from Eu-phorbiaceae family,and has been used in different diseases treatments likes helminthiasis,skin diseases,diabetes,snake-bite,and ***:Depending on the traditional uses of *** and the lack of scientific works,we aimed to conduct some pharmacological tests on its ***:Active constituents of *** were assessed by qualitative ***(2,2-diphenyl-1-picrylhydrazyl)was used for free radical scavenging *** change and mortality rate were used as indicators to assess the toxicity of *** antidiabetic potential was evaluated by oral glucose toler-ance test(OGTT)and alpha-glucosidase enzyme inhibitory *** antidiarrheal activity,castor oil-induced mice were *** test was carried out by disk diffusion assay and MIC ***,analgesic activity was done by acetic acid-induced writhing ***:*** contains alkaloids,carbohydrates,glycosides,flavonoids,tannis,phenolics *** toxicity test ensured the safety of the *** DPPH,the extract showed antioxidant activity with an IC50(con-centration needed to scavenge 50%DPPH)value of 61.65μg/*** phenolic,flavonoid and tannin contents were determined as 124 mg GAE/g,440 mg QE/g and 344 mg GAE/g dried extract,*** OGTT,the ex-tract reduced the blood glucose level *** the alpha-glucosidase inhibitory activity,the plant showed a concentration-dependent reduction of the enzyme at IC50 of 8.53 mg/*** the antidiarrheal test,*** inhibit defecation 30.69%and 53.41%at dose 250 mg/kg and 500 mg/kg,*** extract also showed antibacterial activity against four bacterial strains in the disk diffusion method and minimum inhibitory concen-tration(MIC)values were 62.5μg/mL,62.5μg/mL,125μg/mL and 62.5μg/mL against four bacterial strains,*** an

关键词： Baliospermum solanifolium Antioxidant Antidiabetic Antidiarrheal Antibacterial Analgesic

Evidence of Invariance of Time Scale at Critical Point in Ising Meanfield Equilibrium Equation of State

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Communications in Theoretical Physics 2011年第6期55卷 1109-1112页

作者： Muktish acharyya Ajanta Bhowal acharyya Department of Physics Presidency University86/1 College Street Calcutta-700073India Department of Physics Lady Brabourne CollegeP-1/2 Suhrawardy AvenueCalcutta-700017India

We solve the equilibrium meanfield equation of state of Ising ferromagnet （obtained from Bragg-Williams theory） by Newton-Raphson method. The number of iterations required to get a convergent solution （within a specified accuracy） of equilibrium magnetisation, at any particular temperature, is observed to diverge in a power law fashion as the temperature approaches the critical value. This is identified as the critical slowing down. The exponent is also estimated. This value of the exponent is compared with that obtained from analytic solution. Besides this, the numerical results are also compared with some experimental results exhibiting satisfactory degree of agreement. It is observed from this study that the information of the invariance of time scale at the critical point is present in the meanfield equilibrium equation of state of Ising ferromagnet.

关键词： Ising model meanfield theory Newton-Raphson method relaxation time critical slowing down

Form Invariant Sommerfeld Electrical Conductivity in Generalised d Dimensions

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Communications in Theoretical Physics 2011年第11期56卷 943-944页

作者： Muktish acharyya Department of Physics Presidency University

The Sommerfeld electrical conductivity is calculated in d dimensions following Boltzmann kinetic *** T = 0,the mathematical form of the electrical conductivity is found to remain invariant in any generalised spatial(d... 详细信息

关键词： Sommerfeld electrical conductivity Boltzmann transport theory electronic density of states Fermi Dirac distribution

Pauli Spin Paramagnetism and Electronic Specific Heat in Generalised d-Dimensions

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Communications in Theoretical Physics 2011年第5期55卷 901-903页

作者： Muktish acharyya Department of Physics Presidency University

The variations of pauli spin paramagnetic susceptibility and the electronic specific heat of solids, are caiculated as functions of temperature following the free electron approximation, in generalised d-dimensions. The results are compared and become consistent with that obtained in susceptibility becomes independent of temperature only in three dimensions. Interestingly, the Pauli spin paramagnetic two dimensions.

关键词： electronic density of states Fermi-Dirac distribution