PPR PRESENTATION

1. PRESENTED BY
ZEBA TABASSUM
SARA JABEEN
ECE lll YEAR
SHADAN WOMENS COLLEGE OF
ENGINERING AND
TECHNOLOGY

2. Contents
Introduction
Transmitter design
Receiver design
Rectification antenna
Schottky diode
Sensor circuitry
Advantages and Disadvantages
Conclusion
Future scope
References

3. INTRODUCTION
Always the recharging of mobile phone batteries
has always been a problem for us.
This problem will be solved after our
proposal………!!!!!!!!
 In this paper a new proposal has been made so
as to make the recharging of the mobile phones
is done automatically as you talk in your mobile
phone!

4. 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
Thus the more you talk, the more is your mobile
phone charged!!!!!!! This is new isn’t?!!

5. What Is Microwaves?????
Microwaves are good for transmitting
information from one place to another because
microwave energy can penetrate haze, light rain
and snow, clouds, and smoke.
Shorter microwaves are used in remote sensing.
These microwaves are used for radar like the
Doppler radar used in weather forecasts

6. Microwaves
> Frequency
Range:
3GHZ to 300GHZ
> Remort
Sensing.
> Communication
Industry.
>2.45GHZ ISM
Band.

7. TRANSMITTER DESIGN
The MAGNETRON is a self-contained microwave
oscillator that operates differently from the linearbeam tubes, such as the TWT and the klystron.
——Magnetron is used to produce high-power
output required in radar and communications
equipment
—Microwaves used in mobile communication are
also produced by similar Oscillators

8. Magnetron - Construction

9. 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.

10. PRINCEPLE OF OPREATION
An additional feature to the mobile is RECTENNA.
RECTENNA  Rectification + Antenna
Slotted waveguide
Antenna
mobile signal
circulator
Transmitting station
with the microwave
transmitter
RFcable
sensor
Rectenna
waveguide

11. RECEIVER DESIGN
The basic addition to the mobile phone is going to be
the rectenna.
A rectenna is a rectifying antenna, a special type of
antenna that is used to directly convert microwave
energy into DC electricity.
—A simple rectenna can be constructed from a
schottky diode placed between antenna dipoles.
—The diode rectifies the current induced in the
antenna by the microwaves.
—Rectenae are highly efficient at converting
microwave energy to electricity

12. WHAT’S RECTANNAE???
What’s rectannae you are confused…….it’s
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 AC signal to
PULSATING DC signal.

13. Process of Rectification
Directly converts the microwave signal into DC power.
The efficiency is up to 90% in laboratory environments.
Comprises of a dipoles and diodes.
Usually its elements are arranged in the mesh pattern.

14. Schottky diode
A Schottky barrier diode -- majority carrier device
Common diode -- minority carrier device.
Its reverse recovery time Trr is very short and shorter than 10 nS.
The forward voltage bias of the Schottky barrier diode is under 0.6V.
This is a comparatively ideal diode, such as for a 1 ampere limit
current PN interface.
Power comparison between common diode and Schottky diode
P=0.6*1=0.6W  Schottky diode
P=1.1*1=1.1W  common diode

15. Sensor circuitry
 The sensor circuitry is a simple circuit, which detects if the mobile
phone receives any message signal.
 In India the operating frequency of the mobile phone operators is
generally 900MHz or 1800MHz for the GSM system for mobile
communication.
 A simple yet powerful F to V converter is LM2907.

16. ADVANTAGES
Use of separate chargers is eliminated.
Electricity is saved
The phone can be charged anywhere anytime.
 Wireless energy transfer can potentially recharge
the mobile phones without chords.
 Only one microwave transmitter can serve to all the
service providers in that area.
The need of different types of chargers by different
manufacturers is totally eliminated.

17. DISADVANTAGES
The transmitter and receiver also should be very
powerful devices as the distance increases.
 Slower Charging.
 Wireless transmission of the energy causes some
drastic effects to human body, because of its
radiation.
 More costly.

18. APPLICATIONS
WIRELESS HOME
MOPAR(WIRELESS CHARGING PAD)
MOJO

19. Conclusion
This novel idea minimises the tension of charging
your mobile phones regularly.
—No necessity of Chargers accompanying the
mobile phone
Efficient use of energy transmitted in the form of
microwaves.

20. Future scope
 The wireless charging can even be done using the data exchange as
now only its only been implemented for voice calls.
 With the advent of nanotechnology and MEMS the size of these
rectennas can be brought down to molecular level. It has been
theorized that similar devices, scaled down to the proportions used in
nanotechnology, could be used to convert light into electricity at
much greater efficiencies than what is currently possible with solar
cells. This type of device is called an optical rectenna.

21. Reference
1. 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.
2. 5 Hawkins, Joe, et al, “ Wireless Space Power Experiment,” in
proceedings of the 9th summer Conference of NASA/USRA Advanced
Design Program and Advanced Space Design Program, June 14-18,
1993.
3. MW Medley Jr and MW Medley, ‘Microwave and RF circuits: analysis,
synthesis and design’, Artech House, Norwood, MA, 1993.
4. Falone, Vincent J., “Atmospheric Attenuation of Microwave Power,”
Journal of microwave Power, 5(4), 1970.

22. Thank you