Transcript

“WIRELESS CHARGING OF MOBILE PHONE USING MICROWAVE”

Guide name:Asso. Prof. Ahmeduddin Zaker

Student Name:Mohammed Yaheeya ahmed10081A0439

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Contents

Introduction

Transmitter design

Receiver design

Rectification antenna

Schottky diode

Sensor circuitry

Advantages and Disadvantages

Future scope

Conclusion

Introduction

The mobile can be charged at any time, anywhere.

Mobile can be charged just by making a call.

The microwaves are used to charge the mobile phones.

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 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:SensorRectenna

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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

Microwave region of electromagnetic spectrum

The light travels with the speed of 3*10^5 km/sec We choose s –band of microwave region(2-4GHz) Electromagnetic waves are made up of two parts

1. Electric field

2. Magnetic field These two fields are at right angles to each other

Designation Frequency range

L Band 1 to 2 GHz

S Band 2 to 4 GHzC 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 8

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

Transmitter Design

Magnetron

Magnetron is high power microwave oscillator.

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

Crossed electron and magnetic fields are used.

Self contained microwave oscillator (magnetron)

The Magnetron

Receiver design

An additional feature to the mobile is RECTENNA.

RECTENNA Rectification + Antenna

Transmitting station with the microwave

transmitter

sensor

Rectenna

RT cable

circulator

waveguide

Slotted waveguideAntenna

mobile signal

Process of Rectification

Comprises of a dipoles and diodes.

Usually its elements are arranged in the mesh pattern.

Directly converts the microwave signal into DC power.

The efficiency is up to 90% in laboratory environments.

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.

P=0.6*1=0.6W Schottky diode P=1.1*1=1.1W common diode

Power comparison between common diode and Schottky diode

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.

Advantages

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.

Disadvantages

The transmitter and receiver also should be very powerful devices as

the distance increases.

Wireless transmission of the energy causes some drastic effects to

human body, because of its radiation.

Practical possibilities are not yet applicable as there is no much

advancement in this field.

Conclusion

A novel method of using the power of the microwave to charge the

mobile phones without the use of wired chargers.

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.

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.

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.

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