Institute of Radio Physics and Electronics

Structure for 1-year Diploma Course

MICROWAVE AND MILLIMETREWAVE TECHNOLOGY



PAPER SUBJECT MARKS
THEORETICAL

I Gr.A: Microwave and Millimetrewave Propagation 50

Gr.B: Guided Wave Transmission and Passive Devices 50

II Gr.A: Microwave and mm-wave Generators and Amplifiers 50

Gr.B: Microwave and Millimetrewave Antennas 50

III Gr.A: Microwave and Millimetrewave Measurements 50 Gr.B: Microwave and Millimetrewave Applications 50

IV Gr.A: Communication Techniques 50

Gr.B: Digital Signal Processing 50

Total 400

PRACTICAL

I Study of Modulation and Demodulation Schemes 100
II Study of Sources and Amplifiers 100
III Study of Microwave and Millimetrewave Systems-I 100
IV Study of Microwave and Millimetrewave Systems-II 100

Total 400

Seminar 100
Design of MW and MMW Circuits 100




TOTAL 1000


ANNEXURE – IV(A)
A Brief Note on the Training Programme in

Millimetrewave Technology and Wave Propagation

Microwaves and Millimeter waves are radio waves of wavelength in the range of 100 mm to 1mm. These waves were first put into practical use during World War II. Rapid development in various fields of Electronic Engineering thereafter has led to many new applications, in recent years, in the field of Communication, Information-highways, Instrumentation, Remote Sensing and Weather forecasting etc.

Keeping these application potential in view, Department of Electronics, Govt. of India, under the Technology Development Programme of National Radar Council had initiated projects of R & D nature at the Institute of Radiophysics and Electronics, University of Calcutta, in the area of Microwaves and Millimeterwaves during 1980s. These covered studies related to wave propagation and remote sensing as part of the technology development programme of DOE. Subsequently with further financial support from other funding agencies, which include AICTE, MHRD, DST, DRDO, ADA, UGC and TISCO, different activities were undertaken in the form of delivering electronic hardware, system fabrication and installation at the user's premises and feasibility studies of various propagation impairments related to communication, radar, radiometry and remote sensing.

To sustain and propagate all these R&D activities in millimeterwave/microwave technology in the country, the need for creating scientific and technical manpower in the field was felt. In view of this, DOE, Govt. of India, offered Institute of Radiophysics and Electronics, University of Calcutta, to undertake a Training Programme in Millimeterwave Technology, for a five year period commencing from 1988. Undertaking the programme was possible because an infrastructure worth about Rs. 3 crores had already been developed with funds from various agencies. It is important to note that the programme of this type was the first of its kind in Eastern India.

Under this Programme, expert manpower and a resource group in this area have been developed and a number of consultancy jobs have been extended to the Defence Sectors, Department of Telecommunication, Department of Space, Department of Science and Technology. Further, a number of products developed through this Programme are used in Atmospheric Science.

During the last four and half years, Institute of Radiophysics and Electronics has organised several Refresher Courses, mainly on Microwave, Millimetrewave and Optical Communication, under the Training Programme and extended consultancies to different R & D sectors of our country. Now, this continued programme is in a position to be self sufficient in respect of expenses other than salary component of the staff, sanctioned by the Education Department, Govt. of West Bengal. Such expenses can be met from the earnings through various courses and consultancies, offered by the “Training Programme in Millimeterwave Technology and Wave Propagation”.

ANNEXURE – IV(B)

A Report on the Activities of

S.K. MITRA CENTRE FOR RESEARCH IN SPACE ENVIRONMENT

The S.K. Mitra Center for Research in Space Environment is a multi-department Center established by the University of Calcutta in 2002. The Center was formally inaugurated at the Ionosphere Field Station, Haringhata of the University on March 12, 2002 with Professor Ashish DasGupta as the Director. It functions with the Institute of Radio Physics and Electronics as the nodal department. The Departments of Physics and Chemistry are also involved in its activities. Recently the Indian Space Research Organization (ISRO) has sanctioned the following four research projects under the S.K. Mitra Center:

1. 
   Lower Atmospheric Chemistry: Emission of greenhouse gases from agricultural system, aerosol and other trace gases from urban and remote areas of West Bengal
   

Principal Investigator – Professor N. Purkait, Institute of Radio Physics and

Electronics

Professor S. Sen, Department of Chemistry

Total Sanctioned grant (for 3 years) – Rs. 25.01 lakhs

2. 
   Radio Remote Sensing of the Atmosphere: Radio Remote Sensing of Tropical rain and water vapour and related communication aspects
   

Principal Investigator – Dr. A. Maitra, Institute of Radio Physics and Electronics

Total sanctioned grant (for 3 years) – Rs. 19.27 lakhs

3. 
   Atmospheric Electricity, Electrical Conductivity of Middle Atmosphere and Schumann Resonance
   

Principal Investigator – Professor S.S. De, Institute of Radio Physics and

Electronics

Total sanctioned grant (for 3 years) – Rs. 14.48 lakhs

4. 
   Space Weather
   

Principal Investigator – Professor A. DasGupta, Institute of Radio Physics and

Electronics

Total sanctioned grant (for 3 years) – Rs. 14.06 lakhs
The present research activities of the Center cover different altitude regions of the Earth’s space environment from the lower atmosphere to the Sun.
ANNEXURE – V(A)
RESEARCH ACTIVITIES (EXECUTED)
Solid State Electronics
HBT Amplifiers
Analytical modeling of optimal SiGe-based cascode low noise amplifier (LNA) has been developed. The conventional high-frequency Gummel-Poon model has been modified incorporating lead inductance associated with the emitter, base and collector terminals and then this model has been employed to simulate optimal cascode LNA using PSpice.
Transport in C-Nanotube
The Boltzmann transport equation is applied to study the transport limited by acoustic phonon in Carbon nanotube. Formulation for optical phonons is being conducted.
Si Photonics
The use of Ge rich SiGeC layer for photodetection at telecommunication wavelengths was investigated. The composition of the alloy grown on silicon substrate was evaluated by considering band line up under strain and by suitably modifying experimental absorption spectra for different alloy compositions.

The expression for the fundamental absorption coefficient in SiGe alloy mediated by alloy scattering was derived by using second order perturbation theory.

The values of free carrier absorption calculated at 1300 and 1550 nms differ from the values obtained from Drude model, the values almost universally quoted for silicon based modulators. The present results agree well for low electron concentration, but deviates for larger values.
Optoelectronics
Studies have been made on SiGe-based photodetectors and Heterojunction Bipolar Transistors (HBTs) with special focus on applications in optical communication.
Some work on Quantum Dot Infra-red Photodetectors (QDIPs) was initiated. A new approach of device modeling using Fuzzy Logic has been proposed and applied initially in case of a Si-RFIC inductor.
MSM and IMPATTs
Metal Semiconductor Metal (MSM) devices based on silicon have been fabricated in the microelectronics laboratory for Photodetector application and the I-V & C-V characteristics have been studied under illumination. Also Si p⁺nn⁺ SDR Impatts have been fabricated in the above laboratory. The dc and rf characteristics have been studied for 35 GHz operation.
Effect of junction temperature on the dc and high frequency properties of symmetrically doped DDR Si Impatts has been studied for different bias current density incorporating the effect of space charge and diffusion at mm-wave window frequencies.

Design and simulation of Si/Si_xGe_1-x heterojunction DDR impatts have been carried out. The high frequency characteristics of those devices have been compared with Si heterojunction DDR impatts.

Thermal Processes in Semiconductors
A general formulation of heat generation and distribution processes has been developed. It is made useful to study the contribution towards different processes in some semi-conducting materials used in optoelectronics devices.


Heterojunction IMPATT
The generation of leakage current mechanisms in HJ-IMPATT devices under reversed biased condition has been investigated theoretically. The work in regard to energy distribution of carriers in IMPATT diodes is in progress.
Microwaves and Electromagnetics
Electromagnetics
A theoretical investigation into a new type of improved corrugated horns, which was being carried out at INRAPHEL, was completed at Royal Military College, Canada. At present, a prototype is under fabrication at RMC’s sophisticated workshop.
Microwave/Millimeter-wave and Opto-Microwave Research
A novel coaxial-waveguide oscillator at 34 GHz has been designed and characterized with software characteriztion and hardware fabrication and experimented with yielding a power output of nearly 1.0 watt and having an electronic tuning bandwidth of 20%. It is expected to be useful for microwave communication system.
Novel schemes have been investigated for microwave/ millimeter-wave signal generation using optical heterodyning technique which is very useful for wideband communication systems these days. One scheme , FM side band injection locking of slave laser by master laser provides a very good injection locked output which shows very narrow line width of the output power density spectrum. The low frequency scale model of the scheme establishes salient features of the scheme.
Microwave Tomography
Electromagnetic inverse problems are characterized by their nonlinearity and ill-posedness. The nonlinear nature of electromagnetic inverse problems makes the ill-posedness more severe. By ill-posedness it is meant that one of the following conditions is not satisfied: 1 ) the existence of the solution; 2) the uniqueness of the solution; or 3) the continuity of the inverse mapping. The continuous dependence of the solution on the data is a necessary, but not a sufficient condition for the stability of the solution. While constant progress in computing facilities alleviates the computational burden, the ill-posedness requires good regularization procedures.
Dielectric Resonator Antennas
Some new investigations on Circularly Polarized Dielectric Resonator Antenna for 3G Communication systems have been carried out. A new concept of developing monopole-type low profile wideband DRA for mobile/WLAN applications has been experimented with different DRA structures.
Microstrip Antennas
A novel idea of suppressing cross-polarized radiation from any microstrip radiation introducing a simple defected ground structure (DGS) has been proposed.
A new defected ground structure is designed and experimentally studied for microstrip circuits and antenna applications.
Efficient Computer Aided Designs (CAD) of multilayered microstrip antennas of rectangular and triangular shapes are carried. The design tools can accurately estimate the operating frequency, impedance profile and matching bandwidth.

Mobile Base Station Antennas
High gain low profile base station antennas for three mobile frequencies like UMTS, PCS and Cel have been designed (in collaboration with RMC, Canada) for Spotwave Wireless Inc. (www.spotwave.com), a leading North American Wireless Communication Industry. The new design provides a unique solution for a High Gain (10 dBi) Very Low Profile Printed Antennas for those bands. The related Intellectual Property Right (US Patent) has been purchased by Spotwave.

Space Science and Technology
Lower Atmosphere and Pollution
Some work on total columnar ozone (good ozone) and surface ozone (bad ozone) have been and are being done for Kolkata Megacity and also for some surrounding industrial towns. The total columnar ozone was monitored deploying MICROTOPS II Ozonometer and Sun Photometer from the roof of the CAS Building of the Department. The data thus procured, have been compared with those of TOMS obtained through downloading. The data from these two sources have been compared for the period July 2003 to December 2005. The result of the intercomparison showed excellent agreement among themselves with coefficient of determination of 80% and 84% respectively for the year 2003 and 2005 but that for the year 2004 has been found to be only 47%. The low coefficient of determination is attributed to significantly larger number of forest fires and poor precipition in 2004 compared to 2003 and 2005. It is further noted that even within this period of observation, unlike high- and mid-latitude stations, the total ozone exhibited an increasing trend. In addition, the intensity of UV-B radiation at 305.5 nm, AOT at 1020 nm and water column density at 940 nm have been procured simultaneously with total columnar ozone.
Analysis of the data on surface ozone and its precursors like CO, NO_x and NMHC pertaining to Kolkata and Haldia shows that diurnal trends are prominent only during Autumn to Spring months. The diurnal maximum over Haldia exceeds that for Kolkata where concentration levels of the precursors are higher. The concentration of the NO component of NO_x is found to play a dominant role in controlling the diurnal levels of the surface ozone at any site. In addition the N-E and N-W winds also have significant contribution in exhibiting distinct diurnal pattern on surface ozone during Autumn to Spring months.
Satellite, GPS, Ionosphere

Estimation has been made of Grid Size for Satellite-Based Augmentation System (SBAS) at low latitudes in the Indian zone using Total Electron Content (TEC) data recorded at Calcutta during 1977-1990 and models such as Parameterized Ionospheric Model (PIM 1.6) and International Reference Ionosphere (IRI-95).

The northern limit of the equatorial irregularity belt from GPS observations at Calcutta, a station located near the northern crest of the equatorial anomaly in the Indian longitude sector, during equinoctial months of high sunspot number years 2000-2001has been estimated.
Study has been undertaken of ionospheric perturbations observed in the Total Electron Content (TEC) following the December 26, 2004 Sumatra-Andaman earthquake measured using the GPS and Geo Augmented Navigation (GAGAN) system of ISRO
Ku-Band Rain Attenuation Observations on an Earth-Space Path
Measurements of rain attenuation over an earth-space path are being carried out at Kolkata (22°34' N, 88°29' E), India, since June 2004, by receiving a Ku-band signal at 11.172 GHz from the satellite NSS-6 (geostationary at longitude 95⁰ E). Also, at the receiver site an optical raingauge (ORG) has been operated to measure rain rate with an integration of 10 sec.

The rain attenuation characteristics are studied on two aspects: (i) instantaneous relationship between rain attenuation and point rain rate obtained at the satellite receiving site, and (ii) the statistical scenario based on total observations gathered so far. The knowledge of the dynamic behaviour of rain attenuation with high time resolution is essential for the design of adaptive power control networks to compensate propagation impairments.

Rain Drop Size Distribution Measurements with a Disdrometer
Measurements of drop size distribution (DSD) in rain are being carried out at Kolkata (22°34' N, 88°29' E), India, since June 2004 using an impact type of sensor, developed by Joss and Waldvogel (1967) and manufactured by Distromet Ltd, Switzerland.
The evolution of DSD during rain events has been studied with the disdrometer data. The size distribution is found biased for larger drops during the growing phase whereas smaller drops dominate at the decaying phase of the rain event for the identical rain rates. The DSD data are used to find the integral rainfall parameters (IRPs), such as, liquid water content (W), radar reflectivity factor (Z) and specific attenuation (γ) for the rain events.
Cloud Liquid Water Content and Attenuation at MM Wave Frequencies
The liquid water content in cloud has been obtained from radiosonde data using Salonen’s model which involves cloud detection with the critical humidity function. The seasonal variation of integrated liquid water content (ILWC) has been obtained for the year of 2004 which shows significantly high values of ILWC during June – September, the monsoon period, at Kolkata.
The specific attenuation at mm wave frequencies due to cloud is estimated using the Rayleigh Scattering theory and finding the complex refractivity of water using the double Debye model. The attenuation over the earth-space paths can be considerable at frequencies above 30 GHz whereas the attenuation around 20 GHz is not very significant (~ 0.5 dB).
Atmospheric Studies using GPS Occultation Measurements with CHAMP Data in the Indian Region

The refractivity profiles obtained from the radio occultation measurements of the CHAMP (CHAllenging Minisatellite Payload) satellite using Global Positioning System (GPS) signals are compared with that obtained with the radiosonde data from thirty-three stations in the Indian region. A comparison of temperature profiles obtained from CHAMP data and radiosonde observations indicates generally a good agreement above 10 km, and below 5 km the temperatures given by the CHAMP data are significantly lower than the temperatures measured by radiosonde.

The CHAMP data providing temperature profiles are used to investigate the behaviour of the tropopause in the Indian region. The tropopause height, on the whole, shows very little variation with latitude, whereas the tropopause temperature shows a noticeable increase with latitude.
Potential Gradient of the Atmosphere
The recording of atmospheric potential gradient over Kolkata is being continued by operating a field-mill using the principle of bound charge. The rotor plate of the field mill is connected to earth when exposed to vertical electric field of the atmosphere and alternately connected to the signal processor when shielded by the metal cover stator using a mechanical commutator system.
The amplified signal from the signal processor is recorded digitally in a computer using Sound Forge 4.5 software at a bit rate of 16 bits and a sampling rate of 44100 Hz. The data is taken for one minute at an interval of 15 minutes. The rms value of the data has been taken which is analyzed using Origin 5.0 software.

The data show considerable variations during the total observational period. The average value of the measured potential gradient is about 250 Vm^-1.

VLF Sferics
From Kolkata, recording of VLF Sferics is being continued. The signal coming from antenna is passed through signal processors. The amplified DC signal is recorded in the computer through a data acquisition system having 5 Hz sampling rate. The data are taken round the clock and for each 30 seconds, a data file has been generated.

Recording of transmitted VLF signal VTX1 at 16.3 KHz from one of the Indian Navy Stations at Vijayanarayanam (8⁰25^’59.88^’’N, 77⁰48^’E) is being continued. For this signal, a high Q band-pass filter is used having a centre frequency at 16.3 KHz. The processed AC signal is being recorded round the clock using the sound card by the help of Radio Skypipe software chart recorder.

We observed diurnal variations of VLF Sferics over Kolkata. Meteor and Solar flare effects have also been detected. The analyses of the collected data are communicated for publication.
Recording of VLF Sferics at the same observational frequencies is being carried out at the Tripura University site by a similar setup.

During the period of earthquake on 8^th October, 2005, at the India-Pakistan border, some remarkable spiky variations in the record are observed over Agartala at 6 kHz and 9 kHz frequencies. From October 3, 2005 to October 13, 2005, these spikes with different duration and magnitudes have been recorded at these frequencies. The observed spikes are definitely due to precursors to the India-Pakistan border earthquakes. The analysis is under progress.

From the analysis of the recorded data for vertical potential gradient and VLF Sferics, some correlation study of VLF Sferics with Atmospheric vertical electric field at Kolkata along with its deviation from Global character have been made. Further study in this context is in progress.
Also from the recording of the transmitted VLF signal, we observed Meteor showers through its effects on VLF transmission.
Some collaborative works by conducting campaign with Equatorial Geophysical Research Laboratory at Tirunelveli, Tamilnadu, under Indian Institute of Geomagnetism, are started jointly to measure the vertical potential gradient of the atmosphere, Air-earth current and conductivity of the atmosphere by Gardien condenser. Measurements are taken from Tripura University site from time to time.
Schumann Resonance Spectra Recording
The fabrications of necessary instrumental setups, i.e., antenna, signal processor, software, data logging system, to detect Schumann resonance over Kolkata is being carried out. The analyses of the recorded data for Schumann resonance spectra by using Mu metal core induction coil at the Equatorial Geophysical Research Laboratory (EGRL) at Tirunelveli, Tamilnadu, under the Indian Institute of Geomagnetism, have been made.
Further analyses of the recorded data for vertical potential gradient, VLF Sferics and Schumann resonance are carried out to study the effects of recent Venus transit on 8^th June, 2004, on atmospheric parameters.
Space-time Variation of Raindrop Size Distribution
Some calculations about the variations in raindrop size distribution with space and time are made considering the influence of coalescence and evaporation processes. The influences of some physical parameters on the distribution have been also considered in the analyses.
Characteristics of Lightning and Its Distribution
The lightning discharge spectra of the first mode of the Earth-ionosphere waveguide has been modeled through functions of ionospheric height and the distance from the source in the frequency range between the first and second cut-off frequencies. The mode decomposition process is made useful to obtain the spectrum of the first mode.

Seismo-Electromagnetic Effects during Earthquake
The enhancement of DC electric field during seismic related phenomena initiates the formation of quasi-periodic horizontal inhomogeneities in the ionospheric conductivity. As a result, there will be changes in the lower atmospheric parameters. To estimate the changes in the ionospheric parameters, such as, electron concentration, electron-neutral collision frequency and electron temperature, a model calculation has been made for the lower ionospheric regions. The change of electron temperature has been estimated during enhanced electric field produced in the earthquake region.
Electric Field Due to Cloud Charge Distribution

Some model calculations about the thundercloud electric field into the region between the ionosphere and the earth are conducted. The results may be used to study the nature of variation of electric field in the atmosphere during lightning.

Plasma

Theoretical investigations on non-linear interaction within the ionospheric plasma during HP/HF propagation are being continued. Field solutions of electromagnetic wave equations within the ionospheric anisotropic plasma have been deduced in presence of lightning discharges. Further studies are made on non-linear heating of the lower ionosphere due to lightning discharges.

Communication and Control
Optical Communication
The link length in Dense Wavelength Division Multiplexing (DWDM) using Er Doped Fibre Amplifier (EDFA) and other optical elements considering four wave mixing (FWM) and other impairments for BER = 10(-9) and 10(-12) has been evaluated. In wavelength routed optical network, a transmitted signal remains in optical domain over the entire route (lightpaths) assigned to it between the source and the destination. Different impairments like amplified spontaneous emission (ASE) at EDFA, FWM due to fiber nonlinearties, cross connect switches (XCS’s), wavelength routers (Arrayed waveguide gratings) degrade the signal quality as signal progresses toward its destinations and received BER may be unacceptably high. Mathematical modeling for estimating link length has been carried out.

Quantum Cryptography and Quantum Feedback Control of QED System
The basic perspectives of quantum information and the cryptographic protocol for quantum communication systems have been developed by exploiting the concepts of quantum bits (qubits). The physical feature of quantum dense coding devised by Benett and Wiesener carrying doubling information capacity of a single qubit through entanglement with a second qubit at a distance has been adapted in developing quantum cryptography by observing polarized photons through calcite crystal device.
A new technological aspect of designing quantum feedback control of QED system has also been developed in collaboration with workers at ISI, Kolkata.


ANNEXURE – V(B)
RESEARCH ACTIVITIES (PROPOSED)
Future plan in carrying out fruitful research in the Centre is highlighted in the following paragraphs.
Solid State Electronics & VLSI
IMPATTs
Design and development of 4H-SiC p⁺nn⁺ and p⁺pnn⁺ SDR and DDR diodes will be undertaken. Attempt will be made to fabricate 4H-SiC SDR diodes in microelectronics laboratory. Modeling and simulation of millimeter wave pulsed impatt diode using complex double drift double low high low structures will be undertaken. Large signal computer analysis will be done to predict more accurately the high frequency performance of the device. Computer simulation will be done to study the microwave characteristics of GaN/AlGa_xAs_1-x based SDR and DDR impatts at frequencies above 100GHz.
Transport in C-Nanotube
High field transport in C-nanotube will be studied by using Monte Carlo particle simulation.
Si Photonics
The free carrier absorption at 1300 and 1550 nm in n-Si will be calculated taking into account degeneracy. The electroabsorption spectra in Ge/Si MQWs will be modeled using the earlier theory related to III-V compounds.
Optoelectronics: Photodetectors and Receivers
More studies on Si-based photodetectors are to be carried out alongwith optimization studies for HBT-based Integrated photoreceivers. The work started on quantum dot infra-red photodetectors will be completed. Fuzzy Logic-based modeling approach on photonic devices is being (and will be) carried out. Some studies on semiconductor Quantum Dots will be done.
MOS Devices
Analytical modeling of strained Si channel, grown on relaxed SiGe material, Dual Gate Metal Oxide Semiconductor Devices (DGMOS) will be performed. Calculation of threshold voltage will be carried out for different gate lengths from 100 nm down to 10 nm based on different approaches such as surface potential approach. The terminal currents and voltages will also be calculated. Calculated results will then be compared with the simulation results using SILVACO.
Optoelectronics: Quantum Cascade Lasers
SPICE modeling of the Quantum Cascade Lasers (QCLs) will be developed. This model will be utilized to determine optical modulation depth (OMD), modulation response and bandwidth.
Microwaves and Electromagnetics
Microwave/Millimeter-wave and Opto-Micrwave Research
The coaxial-waveguide oscillator developed at 34 GHz will be extended for analysis at 94 GHz and the analysis will be carried out for circuit parasitics effect to investigate the oscillator performance perturbation.
The FM injection locking scheme will be further investigated for phase locking of multiple laser sources by the ultra-stable microwave/millimeter-wave signal generated by the injection locked master-slave laser couplet. A variation of the phase locking scheme also to be investigated is the synchronous oscillator which in many respect outperforms the phase locking. Software simulation and hardware characterization of the scheme will be taken up for investigation
Microwave Tomography
The proposed work is to develop the reconstruction of the complex permittivity of the body by minimizing the output least square error by an iterative method. We have chosen Gauss –Newton method for the minimization of the output least square error. Several regularization procedures e.g. Levenberg – Marquardt , Tikhonov etc will be applied to combat the ill-posedness of the problem.
3G Printed Antennas
3G Antenna is a new area of research and has become very active in recent years with the growth of the 3^rd generation communication systems. Out of various aspects of 3G antennas, our aim is to develop low profile active and passive antennas with high gain and efficiency. Both DRA and Microstrip elements will be investigated theoretically and experimentally. Various configurations suitable for Laptop computer or other conformal surfaces will also be explored.
GPS Antennas
Several antennas for GPS receiver are commercially available and most of them are basically narrow band with high axial ratio value. We have planned to develop a GPS antenna with very low axial ratio maintaining over the entire GPS band. Over and above, a scheme to develop a multiband planar antenna has been taken up which will include GPS, DCS, PCS and UMTS bands. Both theoretical and experimental studies will be carried out.
Metamaterials
This is a highly focused area of research for workers in both electromagnetics and photonics. The researchers are trying to implement the design for practical applications. Our aim is to develop a feasible design for microwave frequencies and to characterize. RMC, Canada will also take part in this collaborative program. The application of the new structure will be explored as Substrate, Superstrate and FSS for printed antennas.

Space Science, Environment, Space Weather
Lower Atmosphere Physics and Air Pollution
Attempts will be made for collection of more data on Total Columnar Ozone employing both MICROTOPS II and TOMS for long-term study.

Analysis of data on surface ozone and its precursors for Kolkata, Durgapur, Haldia and Howrah for assessing the harmful effects of surface ozone on plant and common public, over urban and industrial sites will be performed.

Procurement of data on methane emission from rice fields of West Bengal during Aman and Boro rice cultivation including the fallow period is planned to obtain yearly integrated flux to re-estimate the methane budget for West Bengal.

Ionospheric Scintillation
Scintillation response in the equatorial region to major geomagnetic storms will be studied as well as ionospheric precursors to generation of equatorial irregularity

Propagation Studies over Earth-Space and Terrestrial Paths
The propagation over the earth-space path at Ku, K and Ka bands can be studied by receiving the satellite downlinks/beacons and the microwave radiometers. The satellite links are suitable for studying the more dominant effects such as, rain attenuation, whereas the weaker effects due to water vapour and cloud are detectable by the radiometric observations. A combination of satellite links and multifrequency radiometric measurements will describe the propagation phenomena caused by different atmospheric parameters.

The propagation study over an earth-space path is particularly important in view of proposed launch of the Indian satellite GSAT-4 which will transmit Ka band beacon signals for propagation experiments in the Indian region. A national programme has been mooted by Satellite Application Centre, Ahmedabad in which the present group will participate with the experimental observations made at Kolkata.

Dual Frequency Radiometric Measurements of Atmospheric Water Vapour and Liquid Water Content