DR.PRAVINKUMAR P.A

Ph. 708 450 0371

nivar_p@yahoo.co.in

Have extensive R&D experience in Antennas, Microwaves, RF, Acoustic data acquisition systems ,Wireless communications techniques etc. The experience includes system definition, formulation of technical specifications, work-plan, software simulation of the circuits / systems, design of hardware, development of circuits, testing of the circuits, system integration and lab testing of the prototype, user evaluation trials (extensive field trials) and transfer of technology for regular production and interaction with the user. Keenly interested in GSM,CDMA, WiFi , Bluetooth  and allied technologies

Visa Status

Presently holding a valid H1B visa and ready to work with any firm in US on contract basis

EDUCATIONAL  QUALIFICATIONS:-

Ph.D. – 1986 Awarded by Cochin University of Science and Technology (CUSAT) Cochin, India for my  thesis entitled `` Shaped beams   from secondary Offset Paraboloidal  reflector due to  modified radiation patterns from Flanged E- plane sectoral horn feeds” This deals with a   

modified feed horn (X-Band) as an illuminator for offset paraboloidal reflector. This setup provided an easy  way to change the Secondary radiation patterns of reflector antennas as per field requirements.

M.Sc - 1978 Master of Science Degree in Physics: Awarded by Sri. Venkateswara University, Tirupati, India.  Semiconductor Electronics” as Optional Subject.The course included the study of the basics  andApplications of analog and digital electronics, Optics, Nuclear Physics, Statistical                     Mechanics with lab and workshop experience .

B.Sc. - 1976 Bachelor of Science Degree in Physics, with Statistics and Maths as the Subsidiary Subjects,  awarded by Kerala University, Trivandrum, Kerala.

TECHNICAL SKILLS SUMMARY: -

Hardware     :   RF design techniques, linear and digital circuits, Antenna techniques with special emphasis on  airborne antennas, underwater acoustic data acquisition systems etc

Computer Languages :   C, C++ &  BASIC

Computer Applications Packages:-

ORCAD, PSPICE, MULTISIM , Windows95,98,2000, XP and Vista versions , DOS, MS OFFICE, MATLAB, PCB DESIGN 

PROFESSIONAL EXPERIENCE: - (All with the Defense Research and Development Organization , Ministry of Defense , Government of India at the Naval Physical and  Oceanographic Laboratory , Cochin , from 1984 Nov to 2007 Aug.)

1 As a senior design and test engineer I was the leader of a small team of engineers and technicians constituted to modify different types of Naval Aircrafts including the composite skinned ones for their enhancement of antisubmarine warfare capabilities .As a specialist in antennas it was my privilege to select and recommend modifications (modkits) on the skin of the aircrafts required to mount necessary antennas so as to work as sensors for the  data reception as well as location finders in the 100 MHz to 200MHz band. In this connection exhaustive theoretical studies and computer simulations of phase and amplitude responses  of VHF stub antennas as mounted on different locations on different types of aircrafts were carried out under my initiative and supervision. The FDTD method was extensively used for the computer simulations . Studies  were carried out  for both fixed wing and rotary wing aircrafts .Consequently a number of Naval Anti submarine aircrafts were modified under my personal supervision and test flown for the satisfactory data reception as well as the position locations of floating sensors  Further to this a number of naval aircrafts including the latest advanced light helicopters (composite skinned) are in line for the modification. These aircrafts include Russian, German , British and Indian origins. This is a ongoing multimillion rupees  program with significant interest to the forces . As stated in the above lines I was  one of the main contributing officers behind this program and being intimately and actively involved from the very beginning was also closely associated with actual flight trials to get a firsthand information about the performance of the system . I am proud to state that I have logged more than hundred flying hours on different types of naval aircrafts  monitoring  systems designed by me perform in actual field conditions.

2.Designed and developed “Search And Rescue” (SAR) beacon for the airborne wing of Indian Navy. This  portable system was designed to work on the International civil distress frequency of 121.5 MHz (AM), and military emergency frequency of 243 MHz (AM) and UHF satellite distress monitoring frequency of 406 MHz (BPSK).  This also consisted of an AM  receiver for 121.5 MHz reception. This project was taken as an import   substitute as substantial numbers were required for the forces saving valuable foreign exchange. Here  the ORCAD was extensively used to simulate and prepare PCB layouts for the boards Also an antenna for the above frequencies was designed and tested and  technology transferred for production.

3 .As an  antenna specialist I was given the task of indigenising various types of airborne antennas in the frequency range of 100 MHz to 200MHz  hitherto  imported into the country at a heavy cost . Using the state of art techniques I designed 5 different types of  airborne antennas as one to one substitute for imported antennas, These antennas were not only physically  compatible  with the antennas they substituted but electrically far superior to them (gain more than 6dB over a similar imported one)  as proved by the radio ranges established using aircrafts. I was also instrumental in enabling an antenna manufacture to apply the technology to commercially produce the items and get military airworthiness certification from competent

authorities .These antennas were used  subsequently to modify different types of aircrafts as described at beginning item.

4..Another very important work entrusted to me was design and development of airborne FM wideband  receiver for the reception and demodulation of VHF signals from sea deployed floating sensors to recover underwater  acoustic data. This receiver was having four independent channels to receive signals from four floating sensors simultaneously.  As a RF expert I designed the 99 channel digital controlled VHF (100MHz to 200MHz) FM receiver along with the Low Noise Preamplifier with built in self test facility . With a sensitivity of better than -103dBm it was giving an aerial range of more than 50Kms with low output distortion (less than 3%) using the airborne antennas developed in sl.no3 above.  The technology was successfully transferred to a State owned public sector manufacturer  for the serial production of the units as per user orders.

5.Designed and developed VHF homing (location finding) system to locate the floating sensors long after their deployment in high seas. The system enabled the pilot to steer the aircraft (fixed wing as well as rotary wing) “on-top” of the selected sensor and read off its coordinates to an accuracy of better than 100 ft . The system consisted of an amplitude modulated double superhetrodyne receiver working in the sensor frequencies between 100 MHz to 200MHz, two antenna switching units, two pairs of phase & amplitude matched antennas, a remote control unit by which all functions are controlled  and a cross needle indicator fitted on the pilot’s console following which the pilot steers the aircraft on-top of the sensor. The system was having a sensitivity of better than –104 dBm and was found to have aerial ranges in excess of 55Kms with a sensor transmitted power of 1 Watt and the achieved target accuracy was better than 100 ft rms. The proving the system on different types of aircrafts was the greatest challenge as the performance of the system depended a great deal on the platform on which it was fitted and no one software can exactly simulate the actual field performance and one has to rely on a great deal of experimentation and innovation to complete the project to the satisfaction of the user. The system was proved on 4 different types of aircrafts and the technology was transferred to a private manufacturer who specialized in RF and related fields and a number of units were produced as per the requirements of the user .

6. I was also made responsible for the  design , development and fabrication of the  acoustic transponder   required for the  testing of active underwater acoustic  sources  in the 2.5KHz  to 19 KHz range as a general laboratory testing equipment .The system consisted of wideband transducer , transmit receive switch, preamplifier , power amplifier , band pass filters, low pass filters, AM  demodulator, level amplifiers,  delay circuits,  timer circuits    The transponder system was assembled in house as a prototype  and exhaustive testing was carried out for satisfactory performance of the system. The simulation software of ORCAD was  used exhaustively while designing the system. A couple of systems were assembled and now in regular use.

7.Involved in the design and development of air deployed underwater acoustic data acquisition and transmitting sensors. This consisted of a hydrophone with long cable ,acoustic preamplifier, analogue filters, Frequency Modulator, RF power amplifiers and flexible multi band VHF antenna along with the water actuated battery and the rugged waterproof housing .It was a cross functional product with inputs from mechanical  and material science groups. The system was proved in the field with the active help of other functional groups and the cooperation of the naval forces. A couple of manufactures were entrusted with the serial production of the system. Being disposable these units are manufactured in quantities of thousands and were of great utility to the forces .It has saved cores of rupees for the nation by avoiding imports. I was in charge of the RF amplifiers , flexible antenna and also a member of the trial team which participated in the field trials .

8..As per the request of the navy I was entrusted with the development of a portable superhetrodyne type acoustic  receiver, which converts the relatively high frequency sonar beacon (used for search and rescue of aircrafts crashed in sea) frequency of 35 KHz to 38 KHz to lower audible frequencies around 1KHz. This was a direct import substitute with drastic cost reduction. This is now standard test equipment with the Naval forces of the country

9.Designed A Ku –Band Radar transponder antenna for the fitment on a floating platform so that it can be detected using the radar fitted on an aircraft.  The antenna is extremely small, lightweight and housed in a low loss random for weatherproofing with good omni directional characteristics. In this I was responsible for the design, development, fabrication, testing, transfer of technology. The platforms were being disposable these antenna requirement was in quantities of hundreds and being a import substitute has the potentially saved considerable money.

10.As a relatively new scientist I was asked to be associated with the team constituted to design & develop, an air deployable underwater bathy buoy for the study of the thermal profile of various layers of the ocean. The system consisted of a underwater thermister probe with 250 meters cable , a VCO, audio conditioning amplifier, FM modulator, RF power amplifier , flexible antenna, floating mechanism with rugged waterproof   container and sea water actuated battery  As I was specialized in RF and antennas I was made responsible for the development of RF portion including the antenna of the system . Successfully developed the  system and technology was transferred for serial production .

Guided a number of Master of Science, Master of Technology & Bachelor of Technology students in there minor and major projects as part of their academic requirements.

CONSULTANCY: -

Consultant for air borne VHF antennas & wild life telemetry systems including portable antennas. Also experienced in CATV antenna consultancy.

I was also a Subject Expert and an External Examiner in RF , Antenna and in allied fields for different Universities at the level of PhD, M.Tech, MSc, and B.Tech.

MEMBERSHIP OF PROFESSIONAL BODIES:-

Senior Member I.E.E.E  (USA)

Member I.E.E.E Antenna & Propagation Society

Member I.E.E.E Aerospace &  Electronic Systems  Society

Member EMI society of India

Hobby:-

       A very keen radio amateur for last 25 years with lot of experimental experience in RF transmitters, RF receivers, Audio amplifiers, Filters, various types of antennas for HF, VHF, UHF and Microwaves, Test and measurement equipments like VSWR meters, Frequency counters, Field strength meters etc.