acknowledgement - Apeejay College of Engineering, Sohna

ACKNOWLEDGEMENT
The Tryst 2010 Team expresses a special acknowledgement to the following people for doing a
dedicated job of reviewing and selecting the papers:
Ritu Garg (Computer Science),Smruti Padhy (Computer Science), Ehtesham Hassan (Computer
Science), Hitesh Shrimali(Electrical), Priyesh Chauhan(Electrical), M Sultan Siddiqui(Electrical),
Anoop C Nair(Electrical), Gaurang Vakil (Electrical), Vimal Singh (Electrical), Shankar (Electrical),
Kiran (Mechanical), Hariharan (Mechanical), Anand Dhruv (Mechanical), Dr. Anima
Nagar(Mathematics), Dhirendra Singh (Mathematics) , Dinbandhu Pradhan (Mathematics),
Sarvesh (Mathematics), Dr. Anurag Rathore(Biochemical), Dharmendra Kumar
Gupta(Chemistry), Rajesh Chhatra (Chemistry), Nem Singh(Chemistry), R.P. Verma (Chemistry),
Bharat Gadakh (Chemistry), Archana Jain (Chemistry), Dr. Joby Joseph(Physics), Gautam Singh
(Physics), Bhupendra Kumar Sharma (Physics), Charu Chandra Korde (Civil), Vivek Kumar
(Instrument Design & Development Centre), Rajendra Singh Malik (Centre Of Polymer),
Immanual (Chemical Engineering) , Jabez (Chemical Engineering)

INDEX
Computer Science
1. WiMAX‐A wireless technology for “Y”oung generation
Praneeth Kumar P, Rajashekar B, Mohan Rao R, Sony Winner, Sujith Simon Reddy G 1
2. Adaptive Steganography: Design of a robust algorithm for cover image ranking and use of
hashing as an authentication mechanism
Sugandha, U. Satya Naga Vineeli 10
3. ANN based character recognizer for mobile devices to help visually challenged
M.Karthikeyan,K.K.Prasanna kumar 15
4. Unsupervised Detection of Unusual Activities
Saurabh Gupta, Ankit Sagwal, Ayesha Choudhary, Subhashis Banerjee , Ankit Narang 21
5. Establishment of Portable Bidirectional Communication for Aiding Rescue Operations after
Disaster
Akhilesh R. Jaiswal, Bharat J. Shinde 27
6. Facial Analysis Between Age Groups Using Distance Matrices
Q. M. Rizvi , R. Asthana 34
7. Gait As A Biometric For Human Recognition
Lekha M.K. Kankane, Yogita A.K. Malpani 38
8. Hiding Sensitive Rule Using Distortion Technique
Lekha M.K. Kankane, Yogita A.K. Malpani 45
9. Image Augmented Inertial Navigation System
M. Sharma, K. Paul, S. Gupta, A. Kansal, S. Dhakar, P. Jain 51
10. iMOUSE – A virtual mouse using face recognition
G.Vaidyanathan, K.Mohan Kumar 55
11. Intelligent transportation system using genetic algorithm for shortest driving time calculation
S.Lokesh raj ,V.Aranganathan ,M.A.karthik kumar 62
12. Internet in Space
Vinay D.Khandagale, Nilesh B. Bhagat 66

13. Neural Networks And Fuzzy Logic In Unmanned Aircraft
S. Thirumurgan, V. S. Venkatraman, M. Praveen 73
14. Steganography
K.Mohan Krishna, K.Agastya Kumar, G.Ganesh Kumar 82
15. The Friend Locator
Harsh Kumar, Harsh Sama, Richa Dhanuka 89
Electrical
16. 3D‐ Face Recognition Using Biometrics
Praneeth Kumar P, Rajashekar B, Mohan Rao R, Sony Winner, Sujith Simon Reddy G 92
17. 4G Technology
Abrar Ahmed T.S., Azarudin. M 105
18. Digital to Digital Converter Using Delta Sigma Modulation
Ketan Bansal, Rhishabh Garg, Shouribrata Chatterjee 114
19. A solution to reduce commercial losses in PowerSystem
B. Karthik, Karthik.Bhattu, 117
20. Density based Energy LEACH Protocol for Wireless Sensor Networks
M. Khulbe, P. Srivastava, R.C. Jain 124
21. Electricity generation: Extraction with conservation
Pawan Kumar 128
22. Euclid Greatest Common Divisor
Shikhar Agarwal , Sandeep Kumar Bindal 131
23. A Proactively Secure Threshold Multisignature Scheme
Subanya.B, Abinesh.K.T, Kavitha Mani.R 134
24. On SHA Family of Algorithms
Srijan Sanket, Anshul Jain 142
25. Optical Layer Technology In Telecommunication Network
Miss Suryateja Nagula 145

26. Optimization of Power Subsystem in a Picosatellite by Battery Module Restructuring
Ganesan Varun Aiyar 151
27. Privacy Threats in E‐passports Using RFID & Biometrics
Sai Prasanth D.V.,Karthick S., Rajarajan R. 157
28. Security Providence for Luggages Using Bluetooth
S.Karthikeyan, S.Kishore, L.Srinivasan 165
29. Usage of PICs’ in EMP bomb resistant circuits
A.V.R.Sharath Chandra, M.Sesha Sai 169
30. Utilization of phase changing materials for thermal management of mobile electronic devices
Sonal Thengane, Nikhil Bhargava 176
31. Wireless Power Transfer using Small Loop Antennas
Karan Goel, Parikshit Vasisht 181
Robotics
32. Anti Hiv Using Nano Robots
Jeevankumar Reddy.Patil, Manikanta.Gummadidala 184
33. Optimizing storage conditions for fruit ripening process
Pallavi Swaroop, Neha Jain 193
34. Remotely Controlled Combatant Robots in Defence Guided by Telepresence and Immersive VR
Systems
V.Guru viswanath ;K.Vikas;A.Vibinth 197
35. Voice Recognized Automated Pen
Gaurav Rajput, Anway Mukherjee 204

Wireless Power Transfer using Small Loop Antennas 181
Wireless Power Transfer using Small Loop Antennas
Karan Goel # , Parikshit Vasisht *
# Department of Electronics and Communication Engineering, Apeejay College Of Engineering, Sohna
* Department of Electronics and Communication Engineering, Apeejay College Of Engineering, Sohna
#
Email:karan.goel09@gmail.com
# 9911163191
*
Email:parikshitvasisht@yahoo.com
* 9899315555
Abstract— We propose an effective design to transfer electricity
up to a non-negligible distance without any connecting wires
using small loop Antennas. For demonstration we have designed
a theoretical model for a prototype to transmit electric power up
to 100W wirelessly over mid-range distance (5m) and light a 60W
bulb. We also give an overview of the techniques used to design
the prototype and compare the simulation and the actual
practical results of the electronics hardware used.
Keywords— Witricity, wireless power transfer, Orcad Pspice
analysis
A. Motivation
I. INTRODUCTION
For the past decade or so there has been a tremendous
growth of autonomous electronic devices (such as I-pods,
mobile phones, laptops, PDA etc) which rely primarily on
stored chemical energy for their power needs. If a technology
can be developed to transmit power wirelessly, it will get rid
of wire mesh and clutter and portable devices could get
charged wirelessly.
inductive coupling in which the coils need not be in resonance
to exchange energy.
C. Our Approach Vs Existing Approach
Serious research has been going on for the past few years to
develop efficient techniques for transferring power wirelessly,
most notably by the team of Kralis of MIT and their company
called Witricity (which is a portmanteau for wireless
electricity)[1].However there are a few notable differences
between our approach and the one used by the MIT team.
We have designed the antenna as a single turn coil which
reduces the complexity and cost of antennas. Also the whole
prototype including the electronics cointaing the RF Amplifier
has been built indigenously using locally available parts to
ensure minimum costs. Our experimental setup can be
represented by the following diagram.
Wireless power transfer can also be used to power nanodevices
like MEMS and bio-tech devices like pacemakers,
which would prevent the repetitive surgeries a patient needs to
undergo for charging his pacemaker.
The project required an extensive practical and theoretical
knowledge of both Engineering electromagnetic theory and
analog electronics and thus provided us with a challenging
opportunity to understand these core concepts of Electrical
engineering at a much deeper level.
B. Theory
The fundamental physics behind wireless energy transfer is
magnetic resonance. This resonance is similar to the
mechanical resonance which can be easily observed in the
shattering of glass experiment. When two coils are in
magnetic resonance, they tend to exchange energy between
themselves while interacting negligibly with Extraneous
objects. Note that the technique is different from simple
Fig. 1 The Prototype setup
Tryst Technical Conference, IIT Delhi 13-14 March, 2010

Wireless Power Transfer using Small Loop Antennas 182
II. POWER SUPPLY DESIGN
The Power Supply is used to generate a High Frequency
sinusoidal current which generates a HF alternating magnetic
field when connected to the resonant coil (Transmitter). The
schematic Diagram below shows Oscillator and the Voltage
Amplifier stage of the power supply
Fig. 5 Actual Digital Oscilloscope Output
Fig. 2 10MHz Colpitts Oscillator and Voltage Amplifier Schematic
The general purpose amplifier transistor Q2N3904 is used
for designing the Oscillator and High voltage transistor
MPSA44 is used in the first stage of the transistor. The first
stage of voltage amplifier is designed with an input impedance
of 50Ω and a voltage gain of about 55dB.
A. Oscillator Design
We decided to use the Colpitts Oscillator to generate the 10
MHz sinusoidal wave due to its low part count and inherent
simplicity and stability. The circuit has been designed using
Cadence Orcad Package and simulated using Pspice. The
Oscillator circuit is shown in figure 2. The simulated output of
oscillator has a peak voltage of ≈ 500mV [figure 4].
Thus we have acceptable performance and acceptable match
between theoretical and practical results for the oscillator.
Note that the noise on the waveform presents no disadvantage
as we simply want to create a high frequency alternating
magnetic field to transfer power and are not doing a
communication protocol. (E.g. Modulation).
B. Voltage Amplifier Design
The ac π-model was used to analyse and design the voltage
amplifier [figure 6].
Fig. 6 Equivalent π-model of voltage Amplifier
The MPSA44 High Voltage transistor is biased with a
collector current of IC=100mA. The circuit schematic is
shown in figure 2.
The Output Power of the voltage amplifier is 1W which is
given to a Class AB Push Pull Power Amplifier with a Power
gain of about 100.This gives an output power of 100W which
is connected to the resonant coils.
Fig. 4 Simulated Oscillator output in Pspice
The Actual Digital Oscilloscope output of the breadboard
prototype is ≈328mV [figure 5].
Tryst Technical Conference, IIT Delhi 13-14 March, 2010

Wireless Power Transfer using Small Loop Antennas 183
III. ANTENNA DESIGN
Two single loop antennas [figure 6] have been designed
which have an impedance of about 8Ω. These antennas are
connected to two bank capacitors whose capacitance can be
varied to tune the resonant frequencies for both single loop
Antennas. The tuning of the two antennas is critical; otherwise
power will not be transferred at maximum efficiency.
Fig. 6 Actual Photo of the Single Loop Antenna
The maximum spacing between the resonant coils (transmitter
and receiver) is calculated using the following derived
equation.
This equation is derived by equating the near field and the far
field due to the loop antennas. R is the distance between the
two coils (Transmitter and Receiver) and λ is the wavelength
of the field. For a frequency of 10 MHz, the maximum
theoretical separation possible between the two resonant coils
is 5m.
IV. CONCLUSIONS
In conclusion, we investigate the feasibility of wireless
power transfer and present a theoretical model for a prototype
which is built from ground up by implementing the basic
concepts of Electronics and Electromagnetics. Note that the
technology is completely safe for Human beings as living
beings are negligibly affected by the resonant magnetic field
generated in our experiment which is of the same order as that
of the Earth’s magnetic field.
We also conclude that the current technique can be refined
and further research can be done to boost efficiency and/or
range and pave the way for commercial exploitation of the
technology.
REFERENCES
The current supplied by the power supply is given by
where I is the alternating current. This current generates a
magnetic field, which is coupled between the two resonant
coils and alternating current is generated in the receiver coil.
Thus power is thus transferred to the receiving antenna which
is connected to a resistive load.
[1] A. Kurs, A. Karalis, R. Moffatt, J.D. Joannopoulos, P. Fisher, M. Soljačić,
“Wireless Power Transfer via Strongly Coupled Magnetic Resonances,”
Science, Vol. 317, 6 July 2007.
[2] A.Malvino and David J Bates, Electronic Principles 7 th Edition, Tata
McGraw Hill Special Indian Edition 2007.
[3] W.H Hyat and J.A Buck, Engineering Electromagnetics 7 th Edition, Tata
McGraw-Hill Special Indian Edition 2007.
.
Tryst Technical Conference, IIT Delhi 13-14 March, 2010