This document describes a proposed technology for wirelessly charging mobile phones through the transmission of microwave signals. The system would include a transmitter that sends microwave signals along with voice data using a slotted waveguide antenna. Mobile phones would be fitted with a rectenna and sensor to receive the signals and convert them to electrical current to charge the phone battery. As the user talks on their phone, it would charge without needing a physical connection. Some benefits include eliminating wired chargers and allowing phones to charge anywhere. Potential issues include safety concerns over radiation exposure and limited charging rates.

1. PRESENTED BY
G.PAVITHRA
ECE- A
FINALYEAR

2. CONTENTS
INTRODUCTION
OBJECTIVE
OUTLINE
PRINCIPLE OF OPERATION
TRANSMITTER
RECEIVER
IMPLEMENTAION
ADVANTAGES
DISADVANTAGES
FUTURE SCOPE
CONCLUSION
REFERENCE

3. INTRODUCTION
A new proposal has made recharging of the mobile phones is
done automatically as you talk in your mobile phone!
The recharging of the mobile phones is independent of their
manufacturer and battery make.
The microwave signal is transmitted from the transmitter along
with the message signal using special kind of antennas called
slotted wave guide antenna at a frequency is 2.45 GHz

4. OBJECTIVE
The main objective of this current proposal is to make the
recharging of Mobile phones independent of their manufacturer
and battery.
We are going to add just a rectenna & a filter to the ordinary
mobiles during manufacturing time…
Thus the more you talk, the more is your mobile phone
charged!!!!!!! This is new isn’t?!!

5. ELECTROMAGNETIC SPECTRUM

6. MICROWAVE REGION
Microwave wavelength range
approximately from 1mm (thickness
of pencil lead) to 30cm (about 12
inches).
The microwave region in
electromagnetic spectrum ranges
from
0.3cm to 300cm.
Microwave region give the
information about the temperature
of the object that emitted
microwaves.

7. WHY WIRELESS CHARGING USING
MICROWAVES ?????
Microwaves are good for transmitting information
from one place to another ( because it penetrate haze
, light rain , snow , clouds etc…).
It has shorter wavelength than remote sensing.
Microwave radiation are considered harmless except
for people with pace makers.

8. Block Diagram

9. PRINCIPLE OF OPERATION
The microwave signal is transmitted along with message signal
using slotted wave guide antenna
The sensor search for the mobile signal , in addition it has a
“RECTENNA”.
Rectenna receives the transmitted power and converts the
microwave power to DC power.

10. TRANSMITTER DESIGN
MAGNETRON
It is a self-contained
microwave oscillator that
operates different from
linear oscillator.
Cross field and magnetic
field are used to produce
high-power output .

11. SLOTTED WAVEGUIDE ANTENNA
It is used as ideal power
transmitter (because of its high
aperture efficiency >95%) .
It has high power handling
capacity .
It has 64 slots of power
uniformly through free space to
the rectenna.

12. RECEIVER DESIGN
The basic addition to a mobile phone is to be rectenna.
Its elements are usually arranged in a mesh pattern .
A simple rectenna is constructed by using a schottky diode .

13. SCHOTTKY
• A Schottky barrier diode is formed by
connecting a metal with a semiconductor.
•The semiconductor material is chosen
from different metals such as
molybdenum, chromium, platinum and
tungsten.
•This diode does not has minority
carriers, its speed is much faster, so its
reverse recovery time(Trr) is very
short and shorter than 10 ns

14. RECTENNA
Its nothing but the
combination of rectifier and
antenna..
Antenna is to receive the
microwave signal and it just
feed the signal to rectifier .
Rectifier is to convert the
microwave energy to
electricity.

15. SENSOR
The operating frequency of the mobile phone is 900MHz or
1800MHz for communication.
LM2907-a simple n F to V converter used as it operates between
this specified range .
To trigger the rectenna circuit to ON and the mobile begins to
charge using the microwave power automatically.
This is required, as the phone has to be charged as long as the
user is talking.

16. IMPLEMENTATIONS
Recently NOKIA has launched this
wireless charging technology in its new
recent mobile model “ NOKIA LUMIA
1020”.
Energy efficient chargers of all size and
shape to match our phone.
They are all quiet compactable , which
means we can use any chargers we like.

17. ADVANTAGES
One can carry their mobile phones any place even to a
remote village.
The use of wired chargers are eliminated.
The phone can be charged at any place and any time.
Electricity can be saved.
The more you talk the more you get charged.

18. DISADVANTAGES
Radiation problem may occur .
Network traffic may cause problem in
charging.
Rate of charging is of minute range .
Charging depends on network coverage.

19. FUTURE SCOPE
In future RECTENNA is used to produce large-scale power
from microwaves beam .
This technology is also applicable for electronic gadgets which
work on batteries and thus saves electricity.
Currently researches are going on, to implement this technology
for laptops.

20. CONCLUSION
A novel use of RECTENNA and a SENSOR in mobile phone
could provide a new dimension in the revelation of mobile
phones.
Thus a great advantage is to carry their mobile phones to any
place is devoid of facilities for charging.

21. REFERENCE
www.scribd.com
www.seminarsonly.com
www.nokialumia.com
www.wikipedia.org
Theodore.S.Rappaport , “Wireless Communications
Principles and Practice”.