Wireless mobile charging through microwaves (2)

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Wireless Charging of Mobile Phones Using Microwaves

BY, AYSWARYA.P.R S7 , EC 13103437 sist

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THANKS TO…SEMINAR COORDINATOR:

DEEPA.V.T MINOSHIMA.M

ASST.PROFESSOR ASST.PROFESSOR

EC DEPT. EC DEPT.

SEMINAR GUIDE:

ANUPAMA.A.S

ASST.PROFESSOR

EC DEPT.

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CONTENTS• INTRODUCTION • WHAT’S HAPPENING• MICROWAVE REGION• FREQUENCY SELECTION• BLOCK DIAGRAM• TRANSMITTER SECTION• RECEIVER SECTION• ADVANTAGES• DISADVANTAGES• APPLICATION• CONCLUSION

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INTRODUCTION 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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CONTD… 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

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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

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Microwave region of electromagnetic spectrum

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

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

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FREQUENCY SELECTION

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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BLOCK DIAGRAM

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TRANSMITTER SECTION

Consists of two parts

MagnetronSlotted waveguide antenna

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MAGNETRON

• Magnetron is a vacuum tube oscillator that generates high-power electromagnetic signals in the microwave frequency range.

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Contd…

• 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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SLOTTED WAVEGUIDE ANTENNA

 It is an Omni-directional antenna

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Contd…

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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RECEIVER SECTION

Basic additions to mobile phone

a. Sensor

b. Rectenna

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SENSOR CIRCUITRY 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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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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RECTENNA

What is Rectenna ?

Rectenna = Rectifier + Antenna.

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Contd… 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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RECTIFYING CIRCUIT 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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ADVANTAGES 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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DISADVANTAGES• 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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APPLICATIONS

As the topic’s name itself it is used for

“ WIRELESS CHARGING OF MOBILE PHONES”

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FUTURESCOPE & CONCLUSION

• 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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Contd…

• Use of rectenna and sensor in mobile phone could provide new dimension in the revolution of MOBILE POWER

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REFERENCES

• Theodore.S.Rappaport , “Wireless Communications Principles and Practice”

• www.seminarprojects.com• www.seminarsonly.com• www.wikipedia.org

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Any questions

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