Submitted to: Submitted by: Mrs.SHIKHA PANDEY Name \ Rollno. (Department of EC) DEPARTMENT OF ELECTRONICS & COMMUNICATION ENGG.

AXIS COLLEGE OF TECHNOLOGY

A Presentation Seminar

On Wireless Charging Of Mobile

Phones Using Microwaves

Contents INTRODUCTIONOBJECTIVE PRINCIPLE OF OPERATIONTRANSMITTERRECEIVER IMPLEMENTAIONADVANTAGESDISADVANTAGESCONCLUSION

Introduction

The mobile can be charged at any time, anywhere automatically

as you talk in your mobile phone!

This technology would eliminate the need for physically

plugging in an Mobile phone.

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

Wireless Charging Of Mobile Phones Using Microwaves

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?!!

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.

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.

Principle of Operation & Block Diagram

Transmitting station with the microwave

transmitter

sensor

Rectenna

RF cable

circulator

waveguide

Slotted waveguideAntenna

mobile signal

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.

TRANSMITTER The MAGNETRON is a self-contained microwave

oscillator.

Cross field and magnetic field are used to produce high-power output .

Efficiency of this high power oscillator lies between 50% and 80%. Electron beam

Energy

Microwave Energy

Cross Field Device

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.

Receiver Design Rectenna:- Microwave

EnergyDC Energy

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”.

It comprises of a dipoles and Schottky barrier

diodes Usually its elements are arranged in the

mesh pattern.

How Receiver Works ?

SCHOTTKY

Scottky Diode•

A Schottky barrier diode is formed byconnecting a metal with a semiconductor.•

The semiconductor material of metalgenerally is chosen from different metals suchas molybdenum, chromium, platinum andtungsten.•

This diode does not has minority carriers, itsspeed is much faster, so its reverse recoverytime(Trr) is very short and shorter than 10 ns.

                                                                                                                                                                                                        

• 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.

What is RECTENNA and how it helps? 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.

•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.

Implementation NOKIA has launched this wireless charging technology in its new 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 as we like.

AdvantagesThe need of different types of chargers by different manufacturers is totally eliminatedLower risk of ELECTRICAL SHOCK or shorting.Convenience.The more you talk the more you get charged.Wireless energy transfers can potentially recharge the mobile phones without chords.

DisadvantagesWireless transmission of the energy causes some

drastic effects to human body, because of its radiation

Process is of high cost.Network traffic may cause problem in charging.Rate of charging is of minute range .Charging depends on network coverage.

FUTURE SCOPEIn 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.

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.

REFERENCE Theoretical and experimental development of 10

and 35 GHz rectennas “IEEE Transactions on

Microwave Theory and Techniques”, vol. 40, no. 6,

June 1992

Theodore.S.Rappaport , “Wireless Communications

Principles and Practice”.

Any Queries..??