PPT on Wireless charging of mobile using microwaves

ByDivya k.j4sm11cs021

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INTRODUCTION

WHAT’S HAPPENING

MICROWAVE REGION

FREQUENCY SELECTION

BLOCK DIAGRAM

TRANSMITTER SECTION

RECEIVER SECTION

ADVANTAGES

DISADVANTAGES

APPLICATION

CONCLUSION

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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

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More you talk more the mobile get charged!

No separate mobile charger

Additives to mobile handsets:

Sensor

Rectenna

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Microwave signal is transmitted from transmitter along with

message signal using slotted waveguide antenna at frequency

2.45 GHz

Charging made universal

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Wavelength : 1 mm-30 cm

Microwave can be used for:

1. Measuring body temperature

2. Transmitting information

3. Remote sensing

4. RADAR

5. Communication

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We choose s –band of microwave region(2-4GHz)

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Designation Frequency range

L Band 1 to 2 GHz

S Band 2 to 4 GHz

C 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

Select license free 2.45 GHz Industrial, Scientific and

Medical (ISM) radio bands

ISM bands are reserved internationally for non-commercial

use of RF electromagnetic fields for industrial, scientific and

medical purpose

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Transmitter has two sections:

◦ Magnetron

◦ Slotted waveguide antenna

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• Magnetron is a vacuum tube oscillator that generates high-

power electromagnetic signals in the microwave frequency

range.

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It is a microwave tube in which electrons generated from a heated

cathode are affected by magnetic and electric fields to produce

microwave radiation

Magnetron is used to produce high-power output required in radar

and communication equipment

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It is an Omni-directional antenna

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Slotted antenna arrays used with waveguides are popular

antenna in navigation, radar and other high-frequency systems

Has high efficiency and gain of 13dB

Here we use frequency of 2.45GHz

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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.

Basic additions to mobile phone

a. Rectenna

b. Sensory Circuit

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What’s rectanna 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.

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Rectenna = Rectifier + Antenna.

Rectenna is a rectifying circuit that converts microwave energy into DC output.

Single Rectenna is approx 23 mm2 , arranged to form an array suitable to the shape of mobile phone.

Very thin as sheets and can be used at the back of the Cell phones

In our design it consists of a single diode power rectifier in “hybrid technology” with improved sensitivity at low power levels.

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The Schottky diode microwave rectifying circuit is used

here as its efficiency is found to be greater than 90%.

To make low cost power rectifier for low and high power

levels of 2.45GHz with good efficiency of rectifying operation

Used to improve transmission efficiency

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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

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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.

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Simple circuit which detects whether the user is making a call

Simple F to V converter, this would serve our purpose

Operating frequency of mobile phone operators for GSM

system for mobile communication in India is 900MHz or

1800MHz

Simple yet powerful F to V converter is LM2907

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SENSOR CIRCUIT

Contd…

On the reception of the microwave signal ,the sensor circuitry

directs rectenna circuit to ON

Rectenna circuit converts microwave energy to dc output

Mobile phone begins to charge using the microwave power as

long as the user talks over cell phone.

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Charging mobiles wirelessly

Saving time for charging

Wastage of power is less

Better than witricity

Get charged as we make call during long journey

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Radiation problems may occur

Network traffic may cause problems in charging

Charging depends on network coverage

Rate of charging may be of minute range

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“ WIRELESS CHARGING OF MOBILE

PHONES”

Use of rectenna and sensor in mobile phone could provide

new dimension in the revolution of MOBILE POWER

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Thus this paper successfully demonstrates a novel method of

using the power of microwave to charge mobile phones

without use of wired chargers.

It provides great advantage to mobile phone users to carry

their phones anywhere even if the place is devoid of facilities

for charging.

Has effect on human beings similar to that from cell phones at

present.

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Ms.Priyanka M.Shah,Ms.Ila D.Paramar,Ms.Heena R.Patel

“Wireless Power Transmission Using Microwave”

www.seminarprojects.com

www.seminarsonly.com

www.wikipedia.org

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