Why do we need wireless
The need of electricity in every nook and
corner of the world
The demand of eco-friendly power
Requirement of efficient and reliable
To reduce dependence on wires and
The ever increasing power demand
In the year 1893,Nikola Tesla
proposed the method of
wireless transmission of
One of the greatest
breakthroughs of science at that
Built the wardenclyffe tower
which could broadcast power
wirelessly using far-field
techniques. Called off as it
radiated power into
surroundings raising issues
Types of wireless energy transfer
Short range– Inductive
Mid range– Resonance
Uses electromagnetic induction
concept-A term for the
interdependence of time-
varying electric and magnetic
Wireless electricity makes use of
“Oscillating electric field
produces magnetic field and
oscillating magnetic field
produces electric field”.
D i f f e r e n t F r e q u e n c y
Property of systems to operate at higher amplitudes at
purticular frequencies known as resonant frequencies than
When 2 objects operate at same resonant frequency they transfer
energy efficiently between them without interfering with the off
Types of Long range/Far field
Radio frequency Transmission
extracts small quantities of energy in
the range 902 and 928 MHz
Disadvantage—interference caused by
Highly directional and coherent
Inefficient for wireless power
11. 11Microwave Transmission
Aims at higher power transfer over longer
distances practically in the range of some miles
Requires a microwave source, antenna and
operates in the frequency range of 1-40GHz
operates at the highest efficiency at 2.45GHz
1.conversion of electrical to microwave
2.Capturing of microwave beams by
3.conversion of microwave to electrical
Major components of the
Microwave power sources used like Klystron,
magnetron, TWT or GaAs MESFETs
Output power is controlled by electronic
Magnetron is most preferred at 2.45 GHz
Has the responsibility of transmitting
Patch, Microstrip, parabolic dish or
slotted waveguide antenna may be used.
Consists of a antenna ,rectifying diodes and
low pass filter.
Rectenna area has to be large.
Important for receiving microwave power
SOLAR POWER SATELLITES:
The most imp. Application or advancement:
absorb light energy from sun.
converted to electric energy and beamed to earth
stations in form of microwave beams
so it can power satellites,aircrafts,even supply electricity
to places where wired connections are not possible at
SPACE POWER TRANSMISSION AND LUNAR BASED
satellites in space can receive microwave signals from
earth and beam it to any place on earth.
in future it encourages power projects on the moon
Applications of long range
1. Efficient and reliable power.
2. Creation of a shock free environment devoid of any
chances of power thefts.
3. Provides solution to the ever increasing demand for
4. A solution to reduce e-waste- a more safe environment.
5. A more cost effective methodology for getting
electricity to your houses which includes paying less for
use of power.
6. SPS are not affected by the day and night cycle leads
to lesser limitations on power harvesting.
1.For short and mid range transfer system has to be set at
the right frequency or there would be no power transfer.
2.For long range the installation cost is high while EMI is
also a concern.
Prospects & Issues:
Wireless electricity is not just a great idea but an urgent
that has to be taken to deal with the current energy crisis.
Even the smallest entity can lead to one of the most
mindboggling dilemmas of the world. Electrons the source
of electricity puts us in a similar fix. It is on us to decide how
to tap these electrons to be useful in our lives.
Wireless electricity comes with its baggage but no can
deny that it is here to stay.
From the discussion its clear that this idea needs awareness
to remove doubts from minds of the people about safety
It requires both support from government and the people
financially and psychologically.
•An article published in the Science Magazine as “Wireless Power
Transfer via Strongly coupled magnetic fields ”
•“Efficient Non-Radiative Midrange Energy Transfer” by Aristeidies
karalis, Marlin Soljacic,2006.