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Kulkarni A.,Society for Applied Microwave Electronics Engineering and Research SAMEER
Procedia Computer Science | Year: 2015

Lightning is usually associated with several natural calamities such as thunderstorms, tornadoes, hail storms etc. A low frequency lightning receiver for severe weather monitoring application is designed and simulated to capture magnetic fields radiated by cloud to ground (CG) lightning in the frequency range of 1-30 KHz with a sensitivity of below 0.959 nT √Hz for 4.7 Ω - 1.4 mH impedance antenna. The receiver includes a loop antenna, an input matching transformer and a low noise amplifier (LNA) along with some application specific circuitry. To capture signals below 1 KHz, receiver's sensitivity must be reduced further to maintain the same detection range. © 2015 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.


Jain A.,Space Applications Center | Sharma R.S.,Space Applications Center | Sinha P.,Society for Applied Microwave Electronics Engineering and Research SAMEER | Bhattacharya A.N.,Space Applications Center
CODEC 2012 - 5th International Conference on Computers and Devices for Communication | Year: 2012

This paper describes a novel compact double balanced upconverter MMIC architecture, which exhibits high conversion gain, good isolation and low spurious responses. The MMIC is realized using a space qualified 0.13μm MHEMT foundry process and is used for the development of Ku to Ka-band upconverter subsystem for on-board applications. It demonstrates a conversion gain of better than 15dB for IF frequency ranges of 12.75-13.25GHz with 8dBm LO drives at 5.35 & 6.95GHz. Six sub-circuits named IF amplifier, IF balun, Quad cold MHEMT mixing cell, LO balun, RF balun & RF amplifier are integrated on a single chip size of 3.7mm × 3mm to get a complete double balanced upconverter. This is the first demonstration of a monolithic MHEMT double balanced upconverter including on-chip IF & RF amplifiers in this frequency range. © 2012 IEEE.


Das S.,Bhabha Atomic Research Center | Chaterjee S.,Society for Applied Microwave Electronics Engineering and Research SAMEER | Kumar A.,Society for Applied Microwave Electronics Engineering and Research SAMEER | Sarkar P.,Society for Applied Microwave Electronics Engineering and Research SAMEER | And 3 more authors.
Physica Scripta | Year: 2011

More than a century has passed since the concept of wave-particle duality was introduced, where electromagnetic (EM) radiation in a dispersionless free space vacuum is represented by a photon that exhibits both corpuscular and wave natures. Historically, discussions have concentrated on the nature of a photon inside a medium that exhibits dispersion in the refraction property, other than free space. In this paper we call mechanical momentum, wave momentum, and try to match our 'thought experiments' with the properties of the photon, or pulse, carrying the EM energy packet. We also try to find the photon's property energy and momentum inside a positive refractive medium. If the medium shows a negative refractive index behavior, then this has profound consequences, and suitable explanations to the classical concept of the corpuscular-wave nature of a photon inside this medium are needed. In this paper, some of the counterintuitive details of the corpuscular-wave nature of a photon inside a negative indexed material are discussed, producing a possible new definition of wave momentum: the concept of 'reactive energy' inside a negative indexed material. These definitions and expressions of 'wave-momentum' and 'reactive energy' pertaining to negative indexed material are new and are discussed and derived by classical means. © 2011 The Royal Swedish Academy of Sciences.


Rambabu S.,Society for Applied Microwave Electronics Engineering and Research SAMEER | Gayatri Vani D.,Satish Dhawan Space Center | Ramakrishna S.S.V.S.,Andhra University | Rama G.V.,Satish Dhawan Space Center | Apparao B.V.,Satish Dhawan Space Center
Journal of Earth System Science | Year: 2013

Accurate prediction of movement and intensity of tropical cyclone is still most challenging problem in numerical weather prediction. The positive progress in this field can be achieved by providing network of observations in the storm region and best representation of atmospheric physical processes in the model. In the present study later part was attempted to investigate the sensitivity of movement and intensity of the severe cyclonic storm AILA to different physical processes in the Weather Research and Forecasting model. Three sets of experiments were conducted for convection, microphysics (MP) and planetary boundary layer (PBL) processes. Model-simulated fields like minimum central surface pressure, maximum surface wind, track and vector displacement error are considered to test the sensitivity. The results indicate that the movement of the system is more sensitive to the cumulus physics and the intensity of the cyclone is sensitive to both PBL and cumulus physics. The combination of Betts Miller Janjic (BMJ) for convection, Yonsei University (YSU) for PBL and Purdue Lin (LIN) for microphysics is found to perform better than other combination schemes. The horizontal and vertical features of the system along with its special features like complete northward movement of the system throughout the travel period and the consistent cyclonic storm intensity until 15 hrs after the landfall could be well simulated by the model. © Indian Academy of Sciences.


Shrivastava P.,Society for Applied Microwave Electronics Engineering and Research SAMEER | Agarwal A.,Society for Applied Microwave Electronics Engineering and Research SAMEER | Shevgaonkar R.K.,Indian Institute of Technology Delhi
Proceedings International Radar Symposium | Year: 2013

Radar systems are used to detect, locate and identify targets. Ultra Short Pulse Radar (USPR) i.e. Ultra Wide Band Radar (UWBR) provides potential advantage over conventional narrow band Radars. One of its main advantages over conventional radar is spatial resolution. With normal radar it is not possible to spot electromagnetically bright points within target, but it is possible with ultra short pulse or UWBR. Due to narrow pulse it is possible to resolve the target within itself. We have developed Ultra Short Pulse Radar operating around 4.5 GHz. With the help of this USPR it has been tried to show that when we are working with ultra short pulse we can improve spatial resolution and resolve the target within itself. © 2013 German Inst of Navigation.


Boiragi I.,Society for Applied Microwave Electronics Engineering and Research SAMEER | Makkar R.,Society for Applied Microwave Electronics Engineering and Research SAMEER | Choudhury B.D.,Society for Applied Microwave Electronics Engineering and Research SAMEER | Mukherji S.,Indian Institute of Technology Bombay | Chalapathi K.,Society for Applied Microwave Electronics Engineering and Research SAMEER
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

This paper details the design and fabrication of an integrated optical waveguide biosensor for antibody/antigen detection. SU-8 polymer is used as the core material to have a bi-conical tapered waveguide fabricated on a silicon substrate. PDMS is used as a buffer layer. The waist diameter of the biconical tapered waveguide has been optimized using Opti-BPM CAD software before fabrication. in addition, the fabrication technique employs simultaneous and single-step formation of the polymer waveguide structures for the guidance of light with V-grooves for low-cost passive alignment of glass optical fiber. The designed biosensor chip demonstrates sensing of FITC tagged goat anti human IgG (GaHIgG) and HIgG immobilized over the sensor surface was the bio receptor. The sensor uses the evanescent field that is present at the surface of the core for rapid and accurate sensing of antibody/antigen in the range of few micrograms per ml. © 2011 SPIE.


Kakatkar S.S.,Society for Applied Microwave Electronics Engineering and Research SAMEER | Ray K.P.,Society for Applied Microwave Electronics Engineering and Research SAMEER
2013 IEEE Applied Electromagnetics Conference, AEMC 2013 | Year: 2013

A radiating longitudinal shunt slot in a waveguide has been analysed by evaluating its internal admittance from its images formed in waveguide walls and using recently developed simple closed form expressions for mutual admittance. The edge condition along transverse direction of slot has been incorporated into the aperture distribution and convergence is accelerated using Shanks' transformation. The resonant length calculated using this simple and accurate analysis is shown to be in close agreement with measured and other theoretical results. © 2013 IEEE.


Kakatkar S.S.,Society for Applied Microwave Electronics Engineering and Research SAMEER | Ray K.P.,Society for Applied Microwave Electronics Engineering and Research SAMEER
2013 International Conference on Microwave and Photonics, ICMAP 2013 | Year: 2013

The internal admittance of a radiating longitudinal slot in the broadwall of rectangular waveguide, required in analyses such as Method of Moments, has been evaluated by considering the images of the slot in waveguide walls. The contribution from this set of infinite images has been evaluated using simple closed form expressions for mutual coupling between slot and its image. The convergence of the series is accelerated using Chebyshev-Toeplitz algorithm. The resonant length calculated using this simple and accurate analysis is shown to be in close agreement with measured results and with other theoretical results. The analysis given here can be extended to include other slot aperture distributions with edge condition in the transverse direction or for rounded end slots. This analysis is useful in the efficient design of waveguide slot arrays. © 2013 IEEE.


Kakatkar S.S.,Society for Applied Microwave Electronics Engineering and Research SAMEER | Irpache P.,Society for Applied Microwave Electronics Engineering and Research SAMEER | Ray K.P.,Society for Applied Microwave Electronics Engineering and Research SAMEER
Progress in Electromagnetics Research Letters | Year: 2016

A novel implementation of N-way Wilkinson power divider using series and parallel combination of coaxial cables has been proposed in this paper. This arrangement results in a very compact power divider at VHF and lower frequencies, has good isolation between all the ports and is capable of handling high power with a low insertion loss. Frequency tuning and phase equalisation are easily accomplished using this technique. The measured results on fabricated 7-way and 4-way power dividers exhibited good input and output matching as well as amplitude and phase balance with an overall length of less than λ/8 at 221 MHz, with potential for further reduction in length. © 2016, Electromagnetics Academy. All rights reserved.


Boiragi I.,Society for Applied Microwave Electronics Engineering and Research SAMEER | Kundu S.,Society for Applied Microwave Electronics Engineering and Research SAMEER | Makkar R.,Society for Applied Microwave Electronics Engineering and Research SAMEER | Chalapathi K.,Society for Applied Microwave Electronics Engineering and Research SAMEER
AIP Conference Proceedings | Year: 2011

This paper explains the influence of different parameters to the sensitivity of an optical waveguide Mach-Zehnder Interferometer (MZI) for real time detection of biomolecules. The sensing principle is based on the interaction of evanescence field with the biomolecules that get immobilized on sensing arm. The sensitivity has been calculated by varying the sensing window length, wavelength and concentration of bio-analyte. The maximum attainable sensitivity for the preferred design is the order of 10-8 RIU at 840 nm wavelength with a sensing window length of 1cm. All the simulation work has been carried out with Opti-BPMCAD for the optimization of MZI device parameters. The SU8 polymers are used as a core and clad material to fabricate the waveguide. The refractive index of cladding layer is optimized by varying the curing temperature for a fixed time period and the achieved index difference between core and clad is Δn=0.0151. The fabricated MZI device has been characterized with LASER beam profiler at 840 nm wavelength. This study demonstrates the effectiveness of the different parameter to the sensitivity of a single mode optical waveguide Mach-Zehnder Interferometer for bio-sensing application. © 2011 American Institute of Physics.

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