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Wireless charging of mobile PPT.


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TO known about the Wireless charging it is helpful.

TO known about the Wireless charging it is helpful.

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  • 2.  In this paper, we deal with the topic of automatic recharging of the mobile phones by use of microwaves.  The microwave signal is transmitted from the transmitter along with the message signal using slotted wave guide antenna at a frequency is 2.45 GHz.  There are minimal addition of a sensor, a “rectenna”, and a filter to the mobile handset.  The need for separate chargers for mobile phones is eliminated and makes charging universal.
  • 4.  Microwaves are electromagnetic wave with frequencies between 300 MHz (0.3 GHz) and 300 GHz  Shorter microwaves are used in remote sensing. These microwaves are used for radar like the Doppler radar used in weather forecasts.  Microwave radiation is still associated with energy levels that are usually considered harmless
  • 5. Power transmission via radio waves can be made more directional, allowing longer distance power beaming . A rectenna may be used to convert the microwave energy back into electricity.  A human safe power density of 1 mW/cm2 can be generated and distributed across a 10 km diameter area corresponds to 750 megawatts total power level.
  • 6. THE MAGNETRON  A microwave tube in which electrons generated from a heated cathode are affected by magnetic and electric fields in such a way as to produce microwave radiation.  Magnetrons can produce continuous power outputs of more than 1 kW at a frequency of 1 GHz.
  • 7.  Cathode is indirectly heated& electrons are generated from a heated cathode, move under the combined force of a radial electric field and an axial magnetic field.  This causes moving electrons to interact synchronously with traveling-wave components of a microwave standingwave pattern.
  • 8. The open space between the plate and the cathode is called the INTERACTION SPACE. In this space the electric and magnetic fields interact to exert force upon the electrons.
  • 9. CROSSED-ELECTRON and MAGNETIC fields are used in the magnetron to produce the high-power output required in radar and communications equipment.
  • 10. A rectenna is a rectifying antenna, converts microwave energy into DC electricity.  The diode rectifies the current induced in the antenna by the microwaves.
  • 11. “An antenna comprising a mesh of dipoles and diodes for absorbing microwave energy from a transmitter and converting it into electric power.”  Microwaves are received with about 85% efficiency at 2.45GHz
  • 12. Rectennae have high efficiency converting microwave energy to electricity above 90%. With the advent of nanotechnology and MEMS the size of these devices can be brought down to molecular level called optical rectenna.
  • 13. •This circuit is based on the optimization of the rectifier in order to have a good matching of the input impedance at desired frequency 2.45GHz and detection sensitivity at low levels of power. • Optimization of circuit is done by introducing the parasitic elements of the Schottky.
  • 14. As our main objective is to charge the mobile phone with the transmitted microwave after rectifying it by the rectenna, the sensor plays an important role.
  • 15. The sensor circuitry detects if the mobile phone receives any message signal. The usage of simple F to V such as LM2907 converters would act as switches to trigger the rectenna circuit to on.
  • 16. Fig shows F to V converter LM2907.It acts as a switch for triggering the rectenna circuitry.
  • 17. Advantages  Charging of mobile phone battery is independent of the battery.  The recharging of the mobile phones is done automatically as you talk in your mobile phone.  The need for separate chargers for mobile phones is eliminated.  Microwave energy apparently has the potential to provide environmentally clean electric power.  The mobile phone users can carry their phones anywhere even if the place is devoid of facilities for charging. Disadvantages  Rectenna is quite bulky , Further reduction in size is required.  Power level density desired for wireless power transmission may exceed the Human safe level.  The Mobile phone Battery is not standardized, hence design of receivers may vary.  The Magnetron at the Base transceiver station dissipates too much Heat. There is a requirement of heat sink.
  • 18. Thus this paper successfully demonstrates a novel method of using the power of the microwave to charge the mobile phones without the use of wired chargers.. A novel use of the rectenna and a sensor in a mobile phone could provide a new dimension in the revelation of mobile phone.
  • 19.  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.  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.  MW Medley Jr and MW Medley, 'Microwave and RF circuits: analysis, synthesis, and design', Artech House, Norwood, MA, 1993.  Falcone, Vincent J., "Atmospheric Attenuation of Microwave Power," Journal of microwave Power, 5(4), 1970.
  • 20. THANK YOU