No Wire is the brief description of the wireless technology and wireless power transmission. this presentation gives the overview of the wireless power transmission and also you can found the different types of the methods used to transfer the power wirelessly i mean the types of the wireless power transmission. ...................................................................................................................................................................................................................................................................

1. Presenting
By
A.S.krishna

2. Contents Abstract
Introduction
History
WPT
Advantages
Disadvantages
Biological Impacts
Applications
Conclusion
Reference

3. Acknowledgement
I’d like to thank our beloved H.O.D sir’s Mr.
N.Sreekanth and Mr. M.L.Dwarakanath Sir and my
guide for their help and guidance . I am also
thankful to my friend’s for their help.

4. Abstract
In this presentation I’d like to provide the complete
details about the wireless power transmission. Here, we
have the contents like Introduction, History, WPT which
means Wireless Power Transmission, Conclusion and
References. In this presentation we’ll see the different
types of the wireless transmission techniques and their
details.

5. Introduction
Wireless Technology is improving widely in this days. We have number
of applications on this wireless technology. Such as WPT, in electrical
and communication departments also.
Wireless power transfer (WPT) or wireless energy transmission is the
transmission of electrical power from a power source to a consuming
device without using solid wires or conductors.
Wireless communication is the transfer of information between two or
more points that are not connected by an electrical conductor.

6. Wireless operations permit services, such as long-range communications, that
are impossible or impractical to implement with the use of wires.
Information is transferred in this manner over both short and long distances.
In this presentation we are mainly looking at the wireless power transmission
and their types and applications.
In wireless power transfer, a transmitter device connected to a power source,
such as the mains power line, transmits power by electromagnetic fields
across an intervening space to one or more receiver devices, where it is
converted back to electric power and utilized.

7. History
The world's first wireless telephone conversation occurred in 1880, when
Alexander Graham Bell and Charles Sumner Tainter invented and
patented the photophone, a telephone that conducted audio conversations
wirelessly over modulated light beams (which are narrow projections of
electromagnetic waves).
There were no practical applications for their invention, which was highly
limited by the availability of both sunlight and good weather.
The photophone also required a clear line of sight between its transmitter
and its receiver.

8. Bell and Tainter's photophone, of 1880.

9. David E. Hughes transmitted radio signals over a few hundred yards by means
of a clockwork keyed transmitter in 1878.
In 1888, Heinrich Hertz demonstrated the existence of electromagnetic waves, the
underlying basis of most wireless technology.
Hertz demonstrated that electromagnetic waves traveled through space in
straight lines, could be transmitted, and could be received by an experimental
apparatus.
Jagadish Chandra Bose around this time developed an early wireless detection
device and helped increase the knowledge of millimeter-length electromagnetic
waves.

10. The term "wireless" came into public use to refer to a radio receiver or transceiver
(a dual purpose receiver and transmitter device), establishing its use in the field
of wireless telegraphy early on; now the term is used to describe modern wireless
connections such as in cellular networks and wireless broadband Internet.
It is also used in a general sense to refer to any type of operation that is
implemented without the use of wires, such as "wireless remote control" or
"wireless energy transfer", regardless of the specific technology (e.g. radio,
infrared, ultrasonic) used.
Guglielmo Marconi and Karl Ferdinand Braun were awarded the 1909 Nobel
Prize for Physics for their contribution to wireless telegraphy.

11. Marconi transmitting the first radio signal
across the Atlantic

12. Inventor Nikola Tesla performed the first experiments in wireless
power transmission at the turn of the 20th century, and may have done
more to popularize the idea than any other individual.
In the period 1891 to 1904 he experimented with spark-excited radio
frequency resonant transformers, now called Tesla coils, which
generated high AC voltages on elevated capacitive terminals.
With these he was able to transmit power for short distances without
wires.

14. Wireless Power Transmission (WPT)
Wireless power transfer (WPT) or wireless energy transmission (WET) is
the transmission of electrical power from a power source to a consuming
device without using solid wires or conductors.
Wireless transmission is useful to power electrical devices in cases where
interconnecting wires are inconvenient, hazardous, or are not possible. In
wireless power transfer, a transmitter device connected to a power source,
such as the mains power line, transmits power by electromagnetic fields
across an intervening space to one or more receiver devices, where it is
converted back to electric power and utilized.

16. There are two different fundamental methods for wireless energy transfer.
They can be transferred using either far-field methods that involve beam
power/lasers, radio or microwave transmissions or near-field using induction.
Both methods utilize electromagnetism and magnetic fields.
In near-field or non-radiative techniques, power is transferred over short
distances by magnetic fields using inductive coupling between coils of wire or
in a few devices by electric fields using capacitive coupling between electrodes.
In radiative or far-field techniques, also called power beaming, power is
transmitted by beams of electromagnetic radiation, like microwaves or laser
beams. These techniques can transport energy longer distances but must be
aimed at the receiver. Proposed applications for this type are solar power
satellites, and wireless powered drone aircraft.

17. Wireless power techniques fall into two categories, non-radiative and radiative.
This two categories are also called as the Near-field and Far-filed Techniques.

18. Near-Field or Non-Radiative Techniques:
The near-field components of electric and magnetic fields die out quickly beyond
a distance of about one diameter of the antenna (Dant). Outside very close ranges
the field strength and coupling is roughly proportional to (Drange/Dant)−3 . Since
power is proportional to the square of the field strength, the power transferred
decreases with the sixth power of the distance (Drange/Dant)−6 or 60 dB per
decade. In other words, doubling the distance between transmitter and receiver
causes the power received to decrease by a factor of 26 = 64.

19. Here we have three types of the near-field or non-radiative techniques.
Inductive Coupling
Capacitive Coupling
Magneto-dynamic Coupling

20. Inductive Coupling:
This coupling is also known as the electro-dynamic induction technic.
The electro-dynamic induction wireless transmission technique relies on the use
of a magnetic field generated by an electric current to induce a current in a
second conductor.
This effect occurs in the electromagnetic near field, with the secondary in close
proximity to the primary. As the distance from the primary is increased, more
and more of the primary's magnetic field misses the secondary.
Even over a relatively short range the inductive coupling is grossly inefficient,
wasting much of the transmitted energy.

23. This action of an electrical transformer is the simplest form of wireless power
transmission. The primary coil and secondary coil of a transformer are not
directly connected; each coil is part of a separate circuit.
Energy transfer takes place through a process known as mutual induction.
Principal functions are stepping the primary voltage either up or down and
electrical isolation.
Mobile phone and electric toothbrush battery chargers, are examples of how this
principle is used. Induction cookers use this method.
The main drawback to this basic form of wireless transmission is short range.
The receiver must be directly adjacent to the transmitter or induction unit in
order to efficiently couple with it.

24. Capacitive Coupling:
In capacitive coupling (electrostatic induction), the dual of inductive coupling,
power is transmitted by electric fields between electrodes such as metal plates.
The transmitter and receiver electrodes form a capacitor, with the intervening
space as the dielectric.An alternating voltage generated by the transmitter is
applied to the transmitting plate, and the oscillating electric field induces an
alternating potential on the receiver plate by electrostatic induction, which
causes an alternating current to flow in the load circuit.
The amount of power transferred increases with the frequency and the
capacitance between the plates, which is proportional to the area of the smaller
plate and (for short distances) inversely proportional to the separation.

27. Capacitive coupling has only been used practically in a few low power
applications, because the very high voltages on the electrodes required to
transmit significant power can be hazardous, and can cause unpleasant side
effects such as noxious ozone production.
In addition, in contrast to magnetic fields, electric fields interact strongly with
most materials, including the human body, due to dielectric polarization.
However capacitive coupling has a few advantages over inductive. The field is
largely confined between the capacitor plates, reducing interference, which in
inductive coupling requires heavy ferrite "flux confinement" cores. Also,
alignment requirements between the transmitter and receiver are less critical.
Capacitive coupling has recently been applied to charging battery powered
portable devices and is being considered as a means of transferring power
between substrate layers in integrated circuits.

28. Magneto-dynamic Coupling:
In this method, power is transmitted between two rotating armatures, one in the
transmitter and one in the receiver, which rotate synchronously, coupled
together by a magnetic field generated by permanent magnets on the armatures.
The transmitter armature is turned either by or as the rotor of an electric motor,
and its magnetic field exerts torque on the receiver armature, turning it. The
magnetic field acts like a mechanical coupling between the armatures.
The receiver armature produces power to drive the load, either by turning a
separate electric generator or by using the receiver armature itself as the rotor in
a generator.

31. This device has been proposed as an alternative to inductive power transfer for
noncontact charging of electric vehicles. A rotating armature embedded in a
garage floor or curb would turn a receiver armature in the underside of the
vehicle to charge its batteries. It is claimed that this technique can transfer
power over distances of 10 to 15 cm (4 to 6 inches) with high efficiency, over 90%.
Also, the low frequency stray magnetic fields produced by the rotating magnets
produce less electromagnetic interference to nearby electronic devices than the
high frequency magnetic fields produced by inductive coupling systems.
A prototype system charging electric vehicles has been in operation at University
of British Columbia since 2012. Other researchers, however, claim that the two
energy conversions (electrical to mechanical to electrical again) make the system
less efficient than electrical systems like inductive coupling.

32. Far-Field or Radiative Techniques:
Far field methods achieve longer ranges, often multiple kilometer ranges, where
the distance is much greater than the diameter of the device(s). The main reason
for longer ranges with radio wave and optical devices is the fact that
electromagnetic radiation in the far-field can be made to match the shape of the
receiving area (using high directivity antennas or well-collimated laser beams).
The maximum directivity for antennas is physically limited by diffraction.
In general, visible light (from lasers) and microwaves (from purpose-designed
antennas) are the forms of electromagnetic radiation best suited to energy
transfer.

33. The Rayleigh criterion dictates that any radio wave, microwave or laser
beam will spread and become weaker and diffuse over distance; the
larger the transmitter antenna or laser aperture compared to the
wavelength of radiation, the tighter the beam and the less it will spread
as a function of distance (and vice versa). Smaller antennae also suffer
from excessive losses due to side lobes.
However, the concept of laser aperture considerably differs from an
antenna. Typically, a laser aperture much larger than the wavelength
induces multi-moded radiation and mostly collimators are used before
emitted radiation couples into a fiber or into space.

34. Here we are mainly implementing the two things to transfer the power.
Microwaves
Lasers

35. Microwaves:
Power transmission via radio waves can be made more directional, allowing
longer distance power beaming, with shorter wavelengths of electromagnetic
radiation, typically in the microwave range.
 A rectenna may be used to convert the microwave energy back into electricity.
Rectenna conversion efficiencies exceeding 95% have been realized. Power
beaming using microwaves has been proposed for the transmission of energy
from orbiting solar power satellites to Earth and the beaming of power to
spacecraft leaving orbit has been considered.

37. Power beaming by microwaves has the difficulty that, for most space applications,
the required aperture sizes are very large due to diffraction limiting antenna
directionality.
For example, the 1978 NASA Study of solar power satellites required a 1-km
diameter transmitting antenna and a 10 km diameter receiving rectenna for a
microwave beam at 2.45 GHz.
These sizes can be somewhat decreased by using shorter wavelengths, although
short wavelengths may have difficulties with atmospheric absorption and beam
blockage by rain or water droplets. Because of the "thinned array curse," it is not
possible to make a narrower beam by combining the beams of several smaller
satellites.

39. Wireless high power transmission using microwaves is well proven.
Experiments in the tens of kilowatts have been performed at Goldstone in
California in 1975 and more recently (1997) at Grand Bassin on Reunion
Island. These methods achieve distances on the order of a kilometer.
Under experimental conditions, microwave conversion efficiency was measured
to be around 54%.
More recently, a change to 24 GHz has been suggested as microwave emitters
similar to LEDs have been made with very high quantum efficiencies using
negative resistance, i.e. Gunn or IMPATT diodes, and this would be viable for
short range links.

41. Lasers:
In the case of electromagnetic radiation closer to the visible region of the spectrum
(tens of micrometers to tens of nanometres), power can be transmitted by
converting electricity into a laser beam that is then pointed at a photovoltaic cell.
This mechanism is generally known as "power beaming" because the power is
beamed at a receiver that can convert it to electrical energy.
Compared to other wireless methods:
 Collimated monochromatic wavefront propagation allows narrow beam cross-section area for
transmission over large distances.
 Compact size: solid state lasers fit into small products.
 No radio-frequency interference to existing radio communication such as Wi-Fi and cell phones.
 Access control: only receivers hit by the laser receive power.

44. Laser "powerbeaming" technology has been mostly explored in military weapons
and aerospace applications and is now being developed for commercial and
consumer electronics. Wireless energy transfer systems using lasers for consumer
space have to satisfy laser safety requirements standardized under IEC 60825.
Other details include propagation and the coherence and the range limitation
problem.
Geoffrey Landis is one of the pioneers of solar power satellites and laser-based
transfer of energy especially for space and lunar missions. The demand for safe
and frequent space missions has resulted in proposals for a laser-powered space
elevator.
NASA's Dryden Flight Research Center demonstrated a lightweight unmanned
model plane powered by a laser beam. This proof-of-concept demonstrates the
feasibility of periodic recharging using the laser beam system.

47. Drawbacks include:
Laser radiation is hazardous. Low power levels can blind humans
and other animals. High power levels can kill through localized spot
heating.
Conversion between electricity and light is inefficient. Photovoltaic
cells achieve only 40%–50% efficiency. (Efficiency is higher with
monochromatic light than with solar panels).
Atmospheric absorption, and absorption and scattering by clouds,
fog, rain, etc., causes up to 100% losses.
Requires a direct line of sight with the target.

48. Advantages of WPT:
 Wireless Power Transmission system would completely eliminates the existing high-tension
power transmission line cables, towers and sub stations between the generating station and
consumers and facilitates the interconnection of electrical generation plants on a global scale.
 It has more freedom of choice of both receiver and transmitters. Even mobile transmitters and
receivers can be chosen for the WPT system.
 The cost of transmission and distribution become less and the cost of electrical energy for the
consumer also would be reduced.
 The power could be transmitted to the places where the wired transmission is not possible.
Loss of transmission is negligible level in the Wireless Power Transmission; therefore, the
efficiency of this method is very much higher than the wired transmission.
 Power is available at the rectenna as long as the WPT is operating. The power failure due to
short circuit and fault on cables would never exist in the transmission and power theft would
be not possible at all.

49. Disadvantages of WPT:
The Capital Cost for practical implementation of WPT seems to be very high and
the other disadvantage of the concept is interference of microwave with present
communication systems.

50. Biological Impacts of WPT:
Common beliefs fear the effect of microwave radiation. But the studies
in this domain repeatedly proves that the microwave radiation level
would be never higher than the dose received while opening the
microwave oven door, meaning it is slightly higher than the emissions
created by cellular telephones. Cellular telephones operate with power
densities at or below the ANSI/IEEE exposure standards. Thus public
exposure to
WPT fields would also be below existing safety guidelines.

51. Applications of WPT:
Generating power by placing satellites with giant solar arrays in
Geosynchronous Earth Orbit and transmitting the power as microwaves to
the earth known as Solar Power Satellites (SPS) is the largest application of
WPT. Another application of WPT is moving targets such as fuel free
airplanes, fuel free electric vehicles, moving robots and fuel free rockets. The
other applications of WPT are Ubiquitous Power Source (or) Wireless
Power Source, Wireless sensors and RF Power Adaptive Rectifying Circuits
(PARC).

52. Conclusion
The concept of Microwave Power transmission (MPT) and Wireless Power
Transmission system is presented. The technological developments in Wireless Power
Transmission
(WPT), the advantages, disadvantages, biological impacts and applications of WPT are
also discussed. This concept offers greater possibilities for transmitting power with
negligible losses and ease of transmission than any invention or discovery heretofore
made.
Dr. Neville of NASA states “You don’t need cables, pipes, or copper wires to receive
power. We can send it to you like a cell phone call – where you want it, when you want
it, in real time”. We can expect with certitude that in next few years’ wonders will be
wrought by its applications if all the conditions are favourable.

53. References:
Agbinya, Johnson I., Ed. (2012). Wireless Power Transfer. River Publishers.
ISBN 8792329233. Comprehensive, theoretical engineering text
Shinohara, Naoki (2014). Wireless Power Transfer via Radiowaves. John Wiley &
Sons. ISBN 1118862961. Engineering text
Tomar, Anuradha; Gupta, Sunil (July 2012). "Wireless power Transmission:
Applications and Components". International Journal of Engineering Research
& Technology (ESRSA Publications Pvt. Ltd.) 1 (5): 1–8. ISSN 2278-0181. Brief
survey of state of wireless power and applications.
Kurs, André; Karalis, Aristeidis; Moffatt, Robert (July 2007). "Wireless Power
Transfer via Strongly Coupled Magnetic Resonances". Science (American
Association for the Advancement of Science) 317: 83–85.

54. Thibault, G. (2014). Wireless Pasts and Wired Futures. In J. Hadlaw, A. Herman,
& T. Swiss (Eds.), Theories of the Mobile Internet. Materialities and Imaginaries.
(pp. 126–154). London: Routledge. A short cultural history of wireless power.
U.S. Patent 4,955,562, Microwave powered aircraft, John E. Martin, et al. (1990).
U.S. Patent 3,933,323, Solid state solar to microwave energy converter system and
apparatus, Kenneth W. Dudley, et al. (1976).
U.S. Patent 3,535,543, Microwave power receiving antenna, Carroll C. Dailey
(1970).
US Patent No. 527857A, Maurice Hutin, Maurice Leblanc, Transformer system
for electric railways, filed November 16, 1892; granted October 23, 1894
US Patent No. 3713148A, Mario W. Cardullo, William L. Parks, Transponder
apparatus and system, filed May 21, 1970; granted January 23, 1973