133089264 Wireless Charging of Mobile Phones Seminar Report (1)
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Transcript of 133089264 Wireless Charging of Mobile Phones Seminar Report (1)
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
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.
Electronics & Communication Engineering, BBDESGI1
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
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
Electronics & Communication Engineering, BBDESGI2
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
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.
Electronics & Communication Engineering, BBDESGI3
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
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.
Fig 1: An EM wave
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).
Electronics & Communication Engineering, BBDESGI4
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
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.
Fig 2: Lumped element circuit
Electronics & Communication Engineering, BBDESGI5
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
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
Electronics & Communication Engineering, BBDESGI6
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
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.
2. Wireless charging
Wireless charging is any of several methods of charging batteries without the
use of cables or device-specific AC adaptors. Wireless charging can be used for a
wide variety of devices including cell phones, laptop computers and MP3 players as
well as larger objects, such as robots and electric cars.
2.1 Different types of wireless charging
There are three methods of wireless charging:
• Inductive charging,
• radio charging
• Resonance charging.
2.2 Inductive charging
It is used for charging mid-sized items such as cell phones, MP3 players and
PDAs. In inductive charging, an adapter equipped with contact points is attached to
the device's back plate. When the device requires a charge, it is placed on a
conductive charging pad, which is plugged into a socket.
2.2.1 Advantages
Electronics & Communication Engineering, BBDESGI7
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
Inductive charging carries a far lower risk of electrical shock, when compared
with conductive charging, because there are no exposed conductors. The ability to
fully enclose the charging connection also makes the approach attractive where water
impermeability is required; for instance, inductive charging is used for implanted
medical devices that require periodic or even constant external power, and for electric
hygiene devices, such as toothbrushes and shavers, that are frequently used near or
even in water. Inductive charging makes charging mobile devices more convenient;
rather than having to connect a power cable, the device can be placed on a charge
plate.
2.2.2 Disadvantages
One disadvantage of inductive charging is its lower efficiency and increased
ohmic (resistive) heating in comparison to direct contact. Implementations using
lower frequencies or older drive technologies charge more slowly and generate heat
for most portable electronics, [excitation needed] the technology-is nonetheless
commonly used in some electric toothbrushes and wet/dry electric shavers, partly for
the advantage that the battery contacts can be completely sealed to prevent exposure
to water. Inductive charging also requires drive electronics and coils that increase
manufacturing complexity and cost.
2.3 Radio charging
It is used for charging items with small batteries and low power requirements,
such as watches, hearing aids, medical implants, cell phones, MP3 players and
wireless keyboard and mice. Radio waves are already in use to transmit and receive
cellular telephone, television, radio and Wi-Fi signals. Wireless radio charging works
similarly. A transmitter, plugged into a socket, generates radio waves. When the
receiver attached to the device is set to the same frequency as the transmitter, it will
charge the device's battery.
2.4 Resonance charging
Electronics & Communication Engineering, BBDESGI8
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
It is used for items that require large amounts of power, such as an electric car,
robot, vacuum cleaner or laptop computer. In resonance charging, a copper coil
attached to a power source is the sending unit. Another coil, attached to the device to
be charged, is the receiver. Both coils are tuned to the same electromagnetic
frequency, which makes it possible for energy to be transferred from one to the other.
The method works over short distances (3-5 meters).
The idea of wireless power transmission is not new. In 1899, Nikola Tesla
wirelessly transmitted 100 million volts of electricity 26 miles to light 200 bulbs and
run an electric motor.
3. Microwave Region
3.1 Microwave frequency bands
• Designation Frequency range
• L Band l to 2 GHz
• S Band 2 to 4 GHz
• C Band 4 to 8 GHz
• X Band 8 to 12 GHz
• K11 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
• V Band 46 to 56 GHz
• W Band 56 to 100 GHz
The S band of the Microwave Spectrum is useful for wireless charging.
Electronics & Communication Engineering, BBDESGI9
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
3.2 Properties of microwave links
• Involve line of sight (LOS) communication technology.
• Affected greatly by environmental constraints, including rain fade.
• Have limited penetration capabilities.
• Sensitive to high pollen count.
• Signals can be degraded during Solar proton event.
3.3 Electro Magnetic Spectrum
Electronics & Communication Engineering, BBDESGI10
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
Fig 3: Electromagnetic spectrum
The electromagnetic spectrum as shown in the Fig 3 is the range of all
possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of
an object is the characteristic distribution of electromagnetic radiation emitted or
absorbed by that particular object.
The electromagnetic spectrum extends from low frequencies used for modern
radio to gamma radiation at the short-wavelength end, covering wavelengths from
thousands of kilometers down to a fraction of the size of an atom. The
long wavelength limit is the size of the universe itself, while it is thought that the
Electronics & Communication Engineering, BBDESGI11
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
short wavelength limit is in the vicinity of the Planck length, although in principle the
spectrum is infinite and continuous.
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.
4. Transmitter Design
Electronics & Communication Engineering, BBDESGI12
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
The Magnetron is a self-contained microwave oscillator that operates
differently from the linear-beam tubes, such as the TWT and the klystron CROSSED-
ELECTRON and MAGNETIC fields are used in the magnetron to produce the high-
power output required in radar and communications equipment.
The magnetron is classed as a diode because it has no grid. A magnetic field
located in the space between the plate (anode) and the cathode serves as a grid. The
plate of a magnetron does not have the same physical appearance as the plate of an
ordinary electron tube. Since conventional inductive-capacitive (LC) networks
become impractical at microwave frequencies, the plate is fabricated into a cylindrical
copper block containing resonant cavities that serve as tuned circuits. The magnetron
base differs considerably from the conventional tube base. The magnetron base is
short in length and has large diameter leads that are carefully.
The cathode and filament are at the center of the tube and are supported by the
filament leads. The filament leads are large and rigid enough to keep the cathode and
filament structure fixed in position. The output lead is usually a probe or loop
extending into one of the tuned cavities and coupled into a waveguide or coaxial line.
The plate structure, shown in Fig 4 is a solid block of copper.
The cylindrical holes around its circumference are resonant cavities. A narrow
slot runs from each cavity into the central portion of the tube dividing the inner
structure into as many segments as there are cavities. Alternate segments are strapped
together to put the cavities in parallel with regard to the output. The cavities control
the output frequency.
The straps are circular, metal bands that are placed across the top of the block
at the entrance slots to the cavities. Since the cathode must operate at high power, it
must be fairly large and must also be able to withstand high operating temperatures. It
must also have good emission characteristics, particularly under return bombardment
by the electrons. This is because most of the output power is provided by the large
number of electrons that are emitted when high-velocity electrons return to strike the
cathode. The cathode is indirectly heated and is constructed of a high-emission
Electronics & Communication Engineering, BBDESGI13
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
material. 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.
Fig 4: Transmitter Design
The plate structure, shown in Fig 4 is a solid block of copper. The cylindrical
holes around its circumference are resonant cavities. A narrow slot runs from each
cavity into the central portion of the tube dividing the inner structure into as many
segments as there are cavities. Alternate segments are strapped together to put the
cavities in parallel with regard to the output. The cavities control the output
frequency.
The cathode and filament are at the center of the tube and are supported by the
filament leads. The filament leads are large and rigid enough to keep the cathode and
filament structure fixed in position. The output lead is usually a probe or loop
extending into one of the tuned cavities and coupled into a wave guide or coaxial line.
5. Receiver Design
Electronics & Communication Engineering, BBDESGI14
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
The basic addition to the mobile phone is going to be the rectenna. A rectenna
is a rectifying antenna, a special type of antenna that is used to directly convert
microwave energy into DC electricity. Its elements are usually arranged in a mesh
pattern, giving it a distinct appearance from most antennae.
A simple rectenna can be constructed from a schottky diode placed between
antenna dipoles. The diode rectifies the current induced in the antenna by the
microwaves. Rectenna are highly efficient at converting microwave energy to
electricity. In' laboratory environments, efficiencies above 90% have been observed
with regularity.
Some experimentation has been done with inverse rectenna, converting
electricity into microwave energy, but efficiencies are much lower-only in the area of
1%. With the advent of nanotechnology and MEMS the size of these devices 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.
Theoretically, high efficiencies can be maintained as the device shrinks, but
experiments funded by the United States National Renewable Energy Laboratory have
so far only obtained roughly 1% efficiency while using infrared light. Another
important part of our receiver circuitry is a simple sensor. This is simply used to
identify when the mobile phone user is talking. 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. The whole setup looks something like this.
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. The
whole setup looks something like this.
5.1 Process of Rectification
Electronics & Communication Engineering, BBDESGI15
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
Studies on various microwave power rectifier configurations show that a
bridge configuration is better than a single diode one. But the dimensions and the cost
of that kind of solution do not meet our objective. This study consists in designing and
simulating a single diode power rectifier in hybrid technology with improved
sensitivity at low power levels. We achieved good matching between simulation
results and measurements thanks to the optimization of the packaging of the Schottky
diode.
Microwave energy transmitted from space to earth apparently has the potential
to provide environmentally clean electric power on a very large scale. The key to
improve transmission efficiency is the rectifying circuit. The aim of this study is to
make a low cost power rectifier for low and high power levels at a.
The cathode and filament are at the center of the tube- and are supported by
the filament leads. The filament leads are large and rigid enough to keep the cathode
and filament structure fixed in position. The output lead is usually a probe or loops
extending into one of the tuned cavities and coupled into a waveguide or coaxial line.
The plate structure, is a solid block of copper. The cylindrical holes around its
circumference are resonant cavities. A narrow slot runs from each cavity into the
central portion of the tube dividing the inner structure into as many segments as there
are cavities. Alternate segments are strapped together to put the cavities in parallel
with regard to the output. The cavities control the output frequency. The straps are
circular, metal bands that are placed across the top of the block at the entrance slots to
the cavities. Since the cathode must operate at high power, it must be fairly large and
must also be able to withstand high operating temperatures.
It must also have good emission characteristics, particularly under return
bombardment by the electrons. This is because most of the output power is provided
by the large number of electrons that are emitted when high-velocity electrons return
to strike the cathode.
The cathode is indirectly heated and is constructed of a high-emission
material. The open space between the plate and the cathode is called the INTERAC
Electronics & Communication Engineering, BBDESGI16
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
TION SPACE. In this space the electric and magnetic fields interact to exert force
upon the electrons. Arranged in a mesh pattern, giving it a distinct appearance from
most antenna. A simple rectenna can be constructed from a schottky diode placed
between antenna dipoles. The diode rectifies the current induced in the antenna by the
microwaves.
Rectenna are highly efficient at converting microwave energy to electricity. In
laboratory environments, efficiencies above 90% have been observed with regularity.
Some experimentation has been done with inverse rectenna, converting electricity into
microwave energy, but efficiencies are much lower-only in the area of 1%.
With the advent of nanotechnology and MEMS the size of these devices 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. Theoretically, high efficiencies can
be maintained as the device shrinks, but experiments funded by the United States
National Renewable Energy Laboratory have so far only obtained roughly 1%
efficiency while using infrared light. Another important part of our receiver circuitry
is a simple sensor. This is simply used to identify when the mobile phone user is
talking. 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.
A Schottky barrier diode is different from a common P/N silicon diode. The
common diode is formed by connecting a P type semiconductor with an N type
semiconductor, this is connecting between a semiconductor and another
semiconductor; however, a Schottky barrier diode is formed by connecting a metal
with a semiconductor. When the metal contacts the semiconductor, there will be a
layer of potential barrier (Schottky barrier) formed on the contact surface of them,
which shows a characteristic of rectification. The material of the semiconductor
usually is a semiconductor of n-type (occasionally p-type), and the material of metal
generally is chosen from different metals such as molybdenum, chromium, platinum
and tungsten. Sputtering technique connects the metal and the semiconductor.
Electronics & Communication Engineering, BBDESGI17
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
A Schottky barrier diode is a majority carrier device, while a common diode is a
minority carrier device. When a common PN diode is turned from electric connecting
to circuit breakage, the redundant minority carrier on the contact surface should be
removed to result in time delay. The Schottky barrier diode itself has no minority
carrier, it can quickly turn from electric connecting to circuit breakage, its speed is
much faster than a common P/N diode, so its reverse recovery time Trr is very short
and shorter than 10 nS. And the forward voltage bias of the Schottky barrier diode is
under 0.6V or so, lower than that of the common PN diode. So, The Schottky barrier
diode is a comparatively ideal diode, such as for a 1 ampere limited current PN
interface.
Frequency of 2.45GHz with good efficiency of rectifying operation. The
objective also is to increase the detection sensitivity at low levels of power. Different
configurations can be used to convert the electromagnetic wave into DC signal, the
study done in showed that the use of a bridge is better than a single diode, but the
purpose of this study is to achieve a low cost microwave rectifier with single Schottky
diode for low and high power levels that has a good performances. This study is
divided on two kinds of technologies the first is the hybrid technology and the second
is the monolithic one. The goal of this investigation is the development of a hybrid
microwave rectifier with single Schottky diode.
The first study of this circuit is based on the optimization of the rectifier in order
to have a good matching of the Input impedance at the desired frequency 2.45GHz.
Besides, the aim of the second study is the increasing of the detection sensitivity at
low levels of power.
This study is divided on two kinds of technologies the first is the hybrid
technology and the second is the monolithic one. The goal of this investigation is the
development of a hybrid microwave rectifier with single Schottky diode. The first
study of this circuit is based on the optimization of the rectifier in order to have a
good matching of the input impedance the desired frequency 2.45GHz.
Electronics & Communication Engineering, BBDESGI18
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
5.2 Antenna Design
The characteristics of an antenna, i.e. Impedance, gain and polarization depend
on the shape of antenna, with the dimensions normalized to the free-space
wavelength.
Spirals are supported to have a nearly frequency independent behavior
between a certain lower and upper frequency, given by the finite size and feed size
respectively. An ideal self-complementary antenna of infinite dimensions has a
theoretical impedance of Zspiral at the feed point and the large bandwidth, no
matching section is used.
Fig 5: Antenna Design
Design of single spiral antenna. Layout of the 8x8 array with 64 diodes (black
devices). In the Fig 5 of single spiral antenna there is diode at centre of antenna which
converts microwave energy to Dc power. From which it can be used to charge cell
phone.
5.3 Sensor circuitry
Electronics & Communication Engineering, BBDESGI19
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
The sensor circuitry is a simple circuit as shown in the Fig 6, which detects if
the mobile phone receives any message signal. This is required, as the phone has to be
charged as long as the user is talking Thus a simple F to V converter would serve our
purpose. In India the operating frequency of the mobile phone operators is generally
900MHz or 1800MHz for the GSM system for mobile communication .Thus the
usage of simple F to Y converter would act as switches to trigger the rectenna circuit
to on.
Fig 6: Sensor circuitry
A simple yet powerful F to V converter is LM2907.using LM2907 would
greatly serve our purpose. It acts as a switch for triggering the rectenna circuitry .The
general block diagram for the LM2097 is given below
Thus on the reception of the signal the sensor circuitry directs the rectenna
circuit to ON and the mobile phone begins to change using the microwave power.
Electronics & Communication Engineering, BBDESGI20
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
5.4 Advantages
• The main advantage of Sensor circuitry is Reduce the usage of
high electricity.
• Make the recharging of the mobile phones independent of their manufacturer.
• Make use of valuable EM energy.
• If Sensor circuitry is Very small circuitry in size.
• More economical than wired charging.
Electronics & Communication Engineering, BBDESGI21
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
6. Conclusion
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.
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.
Wireless charging of mobile phones using Electromagnetic waves can reduce
the problem of electricity and will be helpful for automatic recharging of mobile
phones, which is very much useful in the future
Electronics & Communication Engineering, BBDESGI22
WIRELESS CHARGING OF MOBILE PHONES USING MICROWAVES
References
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[2] 9th Conference of NASA/USRA Advanced Design Program and Advanced
Hawkins, Joe, Etal, "Wireless Space Power Experiment," in Proceedings of the
Space Design Program.
[3] MW Medley, 'Microwave and RF circuit analysis, synthesis, and design.
[4] Falcone, Vincent J., "Atmospheric Attenuation of Microwave Power", Journal of
microwave Power.
[5] California EMF Program 2001 - An Evaluation of the possible risks from electric
and magnetic fields
[6] Glenn Elert. "The Electromagnetic Spectrum, The Physics Hypertextbook".
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[7] "Definition of frequency bands on". Vlf.it. Retrieved 2010-10-16.
[8] Mohr, Peter J.; Taylor, Barry N.; Newell, David B. (2008). "CODATA
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Electronics & Communication Engineering, BBDESGI23