This document proposes a system for wirelessly charging mobile phones using microwaves. It would work by transmitting microwave signals from an antenna at 2.45 GHz, the same frequency used by devices in the industrial, scientific, and medical bands. A receiver attached to each phone would contain a rectenna, which combines a rectifier and antenna to convert the microwave energy into pulsing DC electricity to charge the phone battery. The more a phone is used for calls, the more it would charge without needing to be plugged in. While this could eliminate separate chargers, there are disadvantages like slower charging and potential health effects from the radiation.

1. Wireless Charging Of Mobile
Phones Using Microwaves
Presented By : Quraishi M Shoeb
Alimuddin.
(Electronic & Telecommunication)

2. 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!

3.  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?!!

4. 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

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

6. 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

7. Magnetron - Construction

8. PRINCIPLE OF OPERATION

9. 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.

10. 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

11. 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.

12. 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.

13. 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.

14. Thank you