Institute of Radio Physics and Electronics

The present group will participate in the Megha Tropiqueed Mission programme of ISRO for which already a proposal has been sent. This mission, a joint Indo-French endeavour, will provide a unique facility to study the convective processes in the tropical atmosphere, particularly in the Indian region. The present group proposed to study the rain and atmospheric water in relation to the convective processes utilizing the experimental measurements at Kolkata and climatic parameter data obtained from satellite measurements and models.

Studies on Preicipiation Associated with Thurderstorm under STORM Project
A national programme named, Severe Thunderstorm Observations and Regional Modelling (STORM), is going to be launched DST, New Delhi, to study and model the thunder activities in the eastern region of India. The present group has proposed to study the vertical profile of the rain structure utilizing observations with Micro Rain Radar (MRR) during precipitation associated thunderstorm activities that will indicate the presence of up and down draft associated with the convective processes. An initial research proposal has been submitted which received favourable consideration and a full proposal will be submitted.

Estimate of Climatic Parameters for Indian Region

The study of climatic parameters will be continued using the data from a number of sources namely, (i) Radiosonde, (ii) Satellite data (CHAMP, TRMM etc.), (iii) NMRF, (v) Propagation experiments at Kolkata and Darjeeling.

Atmospheric Electricity
The present recording of VLF sferics data and measurement of electric potential gradient of the earth’s surface over Kolkata and Tripura University site and their analyses as well as interpretation will be continued.
Air-earth current and atmospheric conductivity by Gardien condenser will be measured by lodging campaign with EGRL at the Tripura University site.

Sub-ionospheric transmitted VLF signals in two different frequencies will be recorded from which the fluctuations in the plasma density of the wave path would be correlated to solar and geophysical phenomena by measuring the shift in the terminator time.

The variation of atmospheric conductivity under different solar and geophysical events would be studied directly by measuring the vertical potential gradient.
Theoretical modelling will be developed to explore the influence of plasma density on sub-ionosphere radio path during solar and geophysical events.
Theoretical model will be developed for finding the possible electro-dynamic coupling in the lower ionosphere based on observations of atmospheric vertical potential gradient at the surface of the earth.

With the newly developed signal processor and loop antennas, attempts will be made to detect the Schumann resonance spectra.

To estimate the change in the ionospheric parameters due to precursors of earthquake, modelling work will be conducted. Attempts will be made to explain some observed sferics data at 6, 9, 19.3 and 39 kHz recorded at Agartala site in terms of the precursors of earthquake at the India-Pakistan border.
Further work may be carried out to extend the previous investigations on the rain attenuation in millimeter and sub-millimeter wave region, detection of Schumann resonance spectra with the newly design loop antennas and influence of radiative heat transfer in the design of nanostructure.


Systems Science

Fuzzy Systems
The procedure already adopted can be used for the model identification of any nonlinear, chaotic system. We will identify any existing nonlinear plant with the help of above technique and develop a general approach of designing different types of online indirect or direct adaptive controller.

ANNEXURE – VI(A)
Research Publications in Journals

No	Name of Teacher	Title, journal, vol, page, year
	Abhirup Das Barman, Ipsita Sengupta and P. K. Basu	A simple SPICE model for traveling wave semiconductor laser amplifier, Microwave & Opt. Technol. Lett. (USA) : accepted
	Bratati MukhopadhyaySumitra Ghosh and P. K. Basu	Estimtion of the composition of Si1-x-yGexCy layer on Si for photodetection at 1.3 and 1.55 µms, Opt. Engg., vol. 46, No. 1Jan 07, pp. 1-7.
	Abhijit Biswas and P. K. Basu	Equivalent circuit models of quantum cascade lasers for SPICE simulation of steady state and dynamic response, Journal of Optics A : Pure and Applied Optics, vol. 9, p. 26-32, (2007)
	A.Ghosal and D.Chattopadhyay	Diffusion thermopower in CdSe single quantum wells , Indian J. Phys. 80(4), 405-407 (2006).
	S. Ray, A. Paul and A. DasGupta	Equatorial scintillations in relation to the development of ionization anomaly, Ann. Geo. Phys., 24, 1429-1442, (2006).
	A. DasGupta, A. Paul, S. Ray, A. Das and S. Anantha-krishnan,	Equatorial bubbles as observed with GPS measurements over Pune, India, Radio Sci., 41, RS5S28, doi: 10.1029/2005RS003359, 2006
	S. Ray and A. DasGupta	Geostationary L-band scintillation observations near the crest of Equatorial Anomaly in the Indian Zone, J. Atmos. Sol. Terr. Phys. (UK), 2007 (in press).
	Mukul. K. Das and N. R. Das	Effect of Ge-Composition on the Frequency Response of a Si1-yGey/Si P-i-N Photodetector, Optical Engineering, (2006).
	N. R. Das and Alakananda Mitra	A New Approach to the Modeling of Si – RFIC Inductor, Microwave and Optical Technology Letters, Vol. 48, pp. 1095-1101 (2006).
10.	S. S. De, B. K. De, S. K. Adhikari, B. K. Sarkarand A. Guha	Study of Amplitude Spectrum of VLF Sferics and Vertical Electric Field at Kolkata. Indian J. Radio & Space Phys., 35 (2006), 187

11.	S. S. De, B. K De, S. K. Adhikari, S. K. Sarkar, R. Bera, A. Guha and P. K. Mandal	A Report on Some Specific Features of the Atmospheric Electric Potential Gradient in Kolkata. Indian J. Phys., 80 (2006), 167.
12	S. S. De, A. K. Ghosh, T. K. Ghosh and D. Jana.	Effective Heating in Heavily Doped Semiconductor Devices. Indian J. Pure & Appl. Phys., 44 (2006), 543.
13	S. S. De, B. K De, A. Guha and P. K. Mandal	Detection of 2004 Leonid Meteor Shower by Observing its Effect on VLF Transmission. Indian J. Radio & Space Phys., 35 (2006), 396.
14	S. S. De, B. K. De, S. K. Adhikari, B. K. Sarkar, S. K. Sarkar, A. Guha, P. K. Mandal, S. K. Mandal, H. P. Sardar and M. Ray	The Effect of Recent Venus Transit on Earth’s Atmosphere Accepted for publication in Annals of Geophys.
15	N. N. Purkait, A.K. Saha, Sanghamitra De and D. K. Chakrabarty	Behaviour of methane emission from paddy field of high carbon content, Ind. J Radio Space Phys., vol. 36, pp. 52-58 (2007)
16	A. Maitra and K.Chakravarty	Rain depolarization measurements with a low margin satellite link in Ku band at a tropical location, Electronics Letters, 2007, under review
17	A. Maitra and T. Rakshit Ghosh	Modelling of weighted mean temperature for retrieval of atmospheric water vapour using GPS in the Indian region, Indian Journal of Radio & Space Physics, 2006, under review.
18	S. Mukhopadhyay and A.K. Mandal	Lecture notes: Fuzzy rule extraction using Robust Particle Swarm Optimization. Proceedings of ISNN-2006- LNCS by Springer ,vol. 3971 pp. 762 – 767, May 2006.
19	D. Guha, M. Biswas and J. Y. Siddiqui	Harrington’s formula extended to determine accurate feed reactance of probe-fed microstrip patches IEEE Antennas and Wireless Propagation Letters, Vol. 6, (2007).
20	D. Guha and Y. M. M. Antar	New half-hemispherical dielectric resonator antenna for broadband monopole-type radiation, IEEE Transactions on Antennas and Propagation Vol. 54, N0. 12, pp. 3621-3628, (Dec. 2006).
21	D. Guha and Y. M. M. Antar	Four-element cylindrical dielectric resonator antenna for wideband monopole-like radiation, IEEE Trans. Antennas Propagat., Vol. 54, N0. 9, pp. 2657-2662, (Sept. 2006).
22	M. Biswas, J. Y. Siddiqui, D. Guha, and Y. M. M. Antar	Effect of a cylindrical cavity on the resonance of a circular microstrip patch with variable air-gap, IEEE Antennas and Wireless Propagation Letters, Vol. 5, pp. 418-420, (2006)
23	D. Guha, S. Biswas, M. Biswas, J. Y. Siddiqui and Y. M. M. Antar,	Concentric Ring Shaped Defected Ground Structures for Microstrip Circuits and Antennas to appear in IEEE Antennas and Wireless Propagation Letters, Vol. 5, pp. 402-405, (Dec. 2006).
24	L. C. Y. Chu, D. Guha and Y. M. M. Antar	Comb-shaped wideband dielectric resonator antenna, Electronic Letters, vol. 42, no. 14, pp. 785-786, ( 6^th July, 2006).
25	D. Guha, Y. M. M.Antar, A. Ittiboon, A. Petosa, and D. Lee	Improved design guidelines for the ultra wideband monopole-dielectric resonator antenna, IEEE Antennas and Wireless Propagation Letters, Vol. 5, pp. 373-376, (Dec. 2006).
26	D. Guha and Y. M. M. Antar	Circular microstrip patch loaded with balanced shorting pins for improved input impedance, IEEE Antennas and Wireless Propagation Letters, Vol. 5, pp. 217-219, (2006).
27	S. S. Iqbal, M. Biswas, J. Y. Siddiqui and D. Guha	Performance of cavity backed inverted microstrip broadband antenna Indian J. Radio and Space Phy., Vol. 35, pp. 54-58, (February 2006).
28	Arpita Das and Mahuya Bhattacharyya	FPGA based Embedded System Design for Medical Image Enhancement Technique used in Mask Mode Radiography, Shortlisted for possible publication in International Journal of Computers, Information Technology and Engineering (IJCITAE).