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1. INTRODUTION
With mobile phones becoming a basic part of life, the recharging of mobile phone batteries has always been a problem. The mobile phones vary in their talk time and battery standby according to their manufacturer and batteries. All these phones irrespective of their manufacturer and batteries have to be put to recharge after the battery has drained out. The main objective of this current proposal is to make the recharging of the mobile phones independent of their manufacturer and battery make.
A new proposal has been made so as to make the recharging of the mobile phones is done automatically as you talk in your mobile phone. This is done by use of microwaves. 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 2.45 GHz.
There are minimal additions, which have to be made in the mobile handsets, which are the addition of a sensor, a ‘rectenna’, and a ‘filter’. With the above setup, the need for separate chargers for mobile phones is eliminated and makes charging universal. Thus the more you talk, the more your mobile phone will be charged. With this proposal the manufacturers would be able to remove the talk time and battery standby from their phone specifications.
Thus this seminar successfully demonstrates a novel method of using the power of the microwave to charge the mobile phones without the use of wired chargers. Thus 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. A novel use of the rectenna and a sensor in a mobile phone could provide a new dimension in the revelation of mobile phone.
1.1 The Electromagnetic spectrum
Spectrum results, when a white light is pass through a prism it is separated out into all the colours of the rainbow. This is the visible spectrum. So white light is a mixture of all colours .
Some physicists pretend that light consists of tiny particles which they call photons. They travel at the speed of light. The speed of light is about 300,000,000 meters per second. When they hit something they might bounce off, go right through or get absorbed. What happens is depends on a bit and how much energy they have. If they bounce off something and then go into eye will cause to see the things they have bounced off. Some things like glass and Perspex will let them go through. These materials are transparent. Black objects absorb the photons so it results not be able to see black things. This is the problem has to be sorted out. These poor old physicists get a little bit confused when they try to explain why some photons go through a leaf, some are reflected, and some are absorbed. They say that it is because they have different amounts of energy.
Other physicists pretend that light is made of waves. These physicists measure the length of the waves and this helps them to explain what happens when light hits and leaves. The light with the longest wavelength (red) is absorbed by the green stuff (chlorophyll) in the leaves. There is green light, this is allowed to pass right through or is reflected. (Indigo and violet have shorter wavelengths than blue light.)
It is easy to explain some of the properties of light by pretending that it is made of tiny particles called photons and it is easy to explain other properties of light by pretending that it is some kind of wave.
The visible spectrum is just one small part of the electromagnetic spectrum. These electromagnetic waves are made up of two parts. The first part is an electric field. The second part is a magnetic field. So they are called as electromagnetic waves. The two fields are at right angles to each other. The Various other parts of the emf spectrum and their location can be seen diagrammatically as shown below.
1.2 Electromagnetic waves
Electromagnetic waves can be imagined as a self-propagating transverse oscillating wave of electric and magnetic fields. This diagram shows a plane linearly polarised wave propagating from left to right. An electromagnetic wave is a wave in space with electric and magnetic parts.
Electromagnetic radiation is classified into types according to the frequency of the wave. These types include, in order of increasing frequency, radio waves, microwaves, terahertz radiation, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays. In some technical contexts the entire range is referred to as just light.
Microwaves are electromagnetic waves with wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz (0.3 GHz) and 300 GHz as shown in the Fig 1. This broad definition includes both UHF and EHF (millimeter waves), and various sources use different boundaries. In all cases, microwave includes the entire SHF band (3 to 30 GHz, or 10 to 1 cm) at minimum, with RF. Engineering often putting the lower boundary at 1 GHz (30 cm), and the upper around 100 GHz (3mm).
Apparatus and techniques may be described qualitatively as "microwave" when the wavelengths of signals are roughly the same as the dimensions of the equipment, so that lumped element circuit theory is inaccurate. As a consequence, practical microwave technique tends to move away from the discrete resistors, capacitors, and inductors used with lower frequency radio waves. Instead, distributed circuit elements and transmission-line theory are more useful methods for design and analysis.
Open-wire and coaxial transmission lines give way to waveguides and stripline, and lumped-element tuned circuits as shown in the Fig 2 are replaced by cavity resonators or resonant lines. Effects of reflection, polarization, scattering, diffraction and atmospheric absorption usually associated with visible light are of practical significance in the study of microwave propagation. The same equations of electromagnetic theory apply at all frequencies.
While the name may suggest a micrometer wavelength, it is better understood as indicating wavelengths very much smaller than those used in radio broadcasting. The boundaries between far infrared light, terahertz radiation, microwaves, and ultra-high frequency radio waves are fairly arbitrary and are used variously between different fields of study.
1.3 Need and processing of micro waves
EM wave posses some kind of energy with it. This repots explains about the usage of this valuable energy for recharging of mobile phones, becoming a basic part of life, to avoid the problem of charging the mobile phone batteries without electricity.
The mobile phones vary in their talk time and battery standby according to their manufacturer and batteries. All these phones irrespective of their manufacturer and batteries have to be put to recharge after the battery has drained out. In this aspect a new proposal has been made so as to make the recharging of the mobile phones is done automatically while using the mobile phone. This is done by use of microwaves.
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 2.45GHz.
With minimal additions, which have to be made in the mobile handsets, which are the addition of a sensor, a rectenna and a filter. With the above setup, the need for separate chargers for mobile phones is eliminated and makes charging universal. Thus the more you talk, the more is your mobile phone charged . With this proposal the manufacturers would be able to remove the talk time and battery standby from their phone specifications.
EM wave posses some kind of energy with it. This repots explains about the usage of this valuable energy for recharging of mobile phones, becoming a basic part of life, to avoid the problem of charging the mobile phone batteries without electricity.
