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2. Wireless Charging of Mobile
Phones Using Microwaves
BY,
AYSWARYA.P.R
S7 , EC
13103437
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3. THANKS TO…
SEMINAR COORDINATOR:
DEEPA.V.T MINOSHIMA.M
ASST.PROFESSOR ASST.PROFESSOR
EC DEPT. EC DEPT.
SEMINAR GUIDE:
ANUPAMA.A.S
ASST.PROFESSOR
EC DEPT.
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4. CONTENTS
• INTRODUCTION
• WHAT’S HAPPENING
• MICROWAVE REGION
• FREQUENCY SELECTION
• BLOCK DIAGRAM
• TRANSMITTER SECTION
• RECEIVER SECTION
• ADVANTAGES
• DISADVANTAGES
• APPLICATION
• CONCLUSION
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5. INTRODUCTION
 Mobile phones becoming basic part of life
 Recharging of mobile phones is a big problem
 Objective—to recharge any mobile phone independent of
manufacturer and battery make
 Achieved by recharging battery while talking using
microwaves
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6. CONTD…
 More you talk more the mobile get charged!
 No separate mobile charger
 Removal of talk time and battery stand by from mobile
specifications
 Additives to mobile handsets:
Sensor
Rectenna
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7. WHAT’S HAPPENING?
Microwave signal is transmitted from transmitter along
with message signal using slotted waveguide antenna at
frequency 2.45 GHz
Charging made universal
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9. MICROWAVE REGION
Wavelength : 1 mm-30 cm
Microwave can be used for:
1. Measuring body temperature
2. Transmitting information
3. Remote sensing
4. RADAR
5. Communication
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10. Microwave region of
electromagnetic spectrum
We choose s –band of microwave region(2-4GHz)
Designation Frequency range
L Band 1 to 2 GHz
S Band 2 to 4 GHz
C Band 4 to 8 GHz
X Band 8 to 12 GHz
Ku Band 12 to 18 GHz
K Band 18 to 26 GHz
Ka Band 26 to 40 GHz
Q Band 30 to 50 GHz
U Band 40 to 60 GHz
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11. FREQUENCY SELECTION
 Select license free 2.45 GHz Industrial, Scientific and
Medical (ISM) radio bands
 ISM bands are reserved internationally for non-
commercial use of RF electromagnetic fields for
industrial, scientific and medical purpose
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12. BLOCK DIAGRAM
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13. TRANSMITTER SECTION
Consists of two parts
Magnetron
Slotted waveguide antenna
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14. MAGNETRON
• Magnetron is a vacuum tube oscillator that generates
high-power electromagnetic signals in the microwave
frequency range.
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15. Contd…
• It is a microwave tube in which electrons generated from a
heated cathode are affected by magnetic and electric fields to
produce microwave radiation
• Magnetron is used to produce high-power output required in
radar and communication equipment
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16. SLOTTED WAVEGUIDE ANTENNA
 It is an Omni-directional antenna
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17. Contd…
Slotted antenna arrays used with waveguides are
popular antenna in navigation, radar and other high-
frequency systems
Has high efficiency and gain of 13dB
 Here we use frequency of 2.45GHz
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18. RECEIVER SECTION
 Basic additions to mobile phone
a. Sensor
b. Rectenna
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19. SENSOR CIRCUITRY
 Simple circuit which detects whether the user is making a
call
 Simple F to V converter, this would serve our purpose
 Operating frequency of mobile phone operators for GSM
system for mobile communication in India is 900MHz or
1800MHz
 Simple yet powerful F to V converter is LM2907
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20. CONTD…
 On the reception of the microwave signal ,the sensor
circuitry directs rectenna circuit to ON
 Rectenna circuit converts microwave energy to dc output
 Mobile phone begins to charge using the microwave
power as long as the user talks over cell phone.
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21. RECTENNA
 What is Rectenna ?
 Rectenna = Rectifier + Antenna.
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22. Contd…
 Rectenna is a rectifying circuit that converts microwave
energy into DC output.
 Single Rectenna is approx 23 mm2 , arranged to form an
array suitable to the shape of mobile phone.
 Very thin as sheets and can be used at the back of the Cell
phones
 In our design it consists of a single diode power rectifier
in ―hybrid technology‖ with improved sensitivity at low
power levels.
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23. RECTIFYING CIRCUIT
 The Schottky diode microwave rectifying circuit is used
here as its efficiency is found to be greater than 90%.
 To make low cost power rectifier for low and high power
levels of 2.45GHz with good efficiency of rectifying
operation
 Used to improve transmission efficiency
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24. ADVANTAGES
 Charging mobiles wirelessly
 Saving time for charging
 Wastage of power is less
 Better than witricity
 Get charged as we make call during long journey
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25. DISADVANTAGES
• Radiation problems may occur
• Network traffic may cause problems in charging
• Charging depends on network coverage
• Rate of charging may be of minute range
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26. APPLICATIONS
As the topic’s name itself it is used for
“ WIRELESS CHARGING OF MOBILE PHONES”
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27. FUTURESCOPE & CONCLUSION
• Thus this paper successfully demonstrates a novel method
of using the power of microwave to charge mobile phones
without use of wired chargers.
• It provides great advantage to mobile phone users to
carry their phones anywhere even if the place is devoid
of facilities for charging.
• Has effect on human beings similar to that from cell
phones at present.
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28. Contd…
• Use of rectenna and sensor in mobile phone could provide
new dimension in the revolution of MOBILE POWER
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29. REFERENCES
• Theodore.S.Rappaport , ―Wireless Communications
Principles and Practice‖
• www.seminarprojects.com
• www.seminarsonly.com
• www.wikipedia.org
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31. Any questions
????
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