A presentation "Wireless charging of mobile phones using Microwaves".

1. WIRELESS MOBILE CHARGING USING
MICROWAVES
SEMINAR GUIDE
Prof. Y.K MISHRA
PRESENTED BY-
KAUSHLENDRA SINGH
ROLL No.13419
B.TECH ,3rd
YEAR
ELECTRONICS
ENGINEERING

2. CONTENTS
 INTRODUCTION
 WHAT’S HAPPENING
 MICROWAVE REGION
 FREQUENCY SELECTION
 TRANSMITTER SECTION
 RECEIVER SECTION
 ADVANTAGES
 DISADVANTAGES
 APPLICATION
 CONCLUSION
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3. 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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4. INTRODUCTION [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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5. 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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[7]

6. 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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7. 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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[7]

8. 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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9. BLOCKDIAGRAMOFWHOLESETUP
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[8]

10. TRANSMITTER SECTION
Consists of two parts
– Magnetron
– Slotted waveguide antenna
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11. MAGNETRON
 Magnetron is a vacuum tube oscillator that
generates high-power electromagnetic
signals in the microwave frequency range.
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[7]

12. MAGNETRON [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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13. STRUCTURE OF MAGNETRON
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[8]

14. SLOTTED WAVEGUIDE
ANTENNA
 It is an Omni-directional antenna.
 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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15. Slotted Wave Guide Antenna [5]
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16. RECEIVER SECTION
Basic additions to mobile phone
Sensor
Rectenna
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17. SENSOR CIRCUITRY
 Simple circuit which detects whether the user is making
a call.
 Simple Frequency to Voltage 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 Frequency to Voltage converter is
LM2907
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18. SENSOR CIRCUITRY [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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19. Sensor Circuitry
LM 2907 IC
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[8]

20. RECTENNA
 What is Rectenna?
 Rectenna is a rectifying circuit that converts
microwave energy into DC output.
 Single Rectenna is approx 23 mm , 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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21. 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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22. RECTIFICATIONRECTENNA
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Rectifying Circuit [4]

23. 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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24. 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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25. APPLICATION
 As the topic’s name itself it is used for
“ WIRELESS CHARGING OF MOBILE
PHONES”
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26. FUTURE SCOPE
 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.
 Use of rectenna and sensor in mobile phone could provide
new dimension in the revolution of mobile power.
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27. CONCLUSION
 Thus this technique successfully demonstrates a
novel method of using the power of the microwave to
charge the mobile phones without the use of wired
chargers.
 Thus this method provides great advantage to the
mobile phone users to carry their phones anywhere
even if the place is devoid of facilities for charging.
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28. REFERENCES
[1]. Theodore.S.Rappaport , “Wireless Communications
Principles and Practice”
[2]. Wireless Power Transmission – A Next Generation
Power Transmission System, International Journal of
Computer Applications Volume 1 – No. 13.
[3]. Lander, Cyril W. "2. Rectifying Circuits". Power
electronics London: McGraw-Hill. 3rd edition, 1993.
[4]. Tae-Whan yoo and Kai Chang, "Theoretical and
Experimental Development of 10 and 35 GHz rectennas"
IEEE Transaction on microwave Theory and
Techniques, vol. 40. NO.6. June.1992.
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29. REFERENCES [contd.]
[5]. Pozar, David M. Microwave Engineering Addison–
Wesley Publishing Company,1993.
[6]. Wireless Power Transmission – A Next Generation
Power Transmission System, International Journal of
Computer Applications Volume 1 – No. 13.
[7]. www.seminarsonly.com
[8]. International Journal of Innovative Research in
Science, Engineering and Technology, Published on
Feb 1,2014
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