This document discusses wireless power transmission using microwaves and solar power satellites. It begins with an introduction explaining the need for wireless power transmission. Then it covers the history of wireless power transmission pioneered by Nikola Tesla and experiments by NASA. It describes how space-based wireless power transmission can use microwaves or lasers. The key components of a microwave wireless power transmission system are a DC to microwave converter, transmitting antenna, and rectenna to convert microwaves back to DC. A conceptual solar power satellite system is shown. Efficiencies are low currently but may improve with metamaterials.

1. WIRELESS POWER TRANSMISSION
USING MICROWAVES AND SOLAR
POWER SATELLITES
INSTITUTE OF TECHNICAL EDUCATION &
RESEARCH
BY
DEBARUN SENGUPTA
1011016293
GUIDED BY:
PROFESSOR MIHIR NARAYAN MOHANTY

2. DISCUSSION ROADMAP
 INTRODUCTION
 HISTORY OF WIRELESS POWER TRANSMISSION
 METHODS OF SPACE BASED WPT
 DC-RF CONVERSION
 RF-DC CONVERSION USING RECTENNA
 CONCEPT OF SOLAR POWER SATELLITE
 CONCLUSION AND DISCUSSION

3. INTRODUCTION
WHY WE NEED WIRELESS POWER TRANSMISSION?
 We are in an age of serious energy crisis and resource crunch.
 Wireless power transmission from space using Solar
power satellites.
 Wireless energy transmission to distant remote islands.
 Powering aerial vehicles from ground.

4. HISTORY OF WPT
 Nicola Tesla considered as the
Father of WPT.
 Tesla applied the principle of
resonance to transfer power wirelessly.
 William Brown of Raytheon
company used MWPT for wireless
powered helicopter.
www.pancea-bocarf.org

5. HISTORY(CONTINUED)
 In 1975 a grand MWPT
experiment occurred at
NASA Jet Propulsion
Laboratory Goldstone
facility.
 It generated 37 KW of
power that was sent to a
rectenna system , located
one mile away, which
collected and converted
84% of the energy to DC. www.mwrf.com

6. METHODS OF SPACE BASED WPT
 Far Term Space Systems to beam power to Earth
 Light-Wave Systems
 Radio-Wave WPT System
 In case of light-wave system we use laser beam for
wireless power transmission.
 In case of radio-wave power transmission systems we use
microwaves for wireless power transmission.

7. COMPARISON
ATTRIBUTE MWPT LASER
INTERFERENCE Radio frequency
interference
None except astronomical
APERTURE SIZE Large, so system is very
large
small
ATTENUATION Penetrates clouds and
rains
Stopped by clouds
EFFICIENCY (SPACE) HIGH IMPROVING
EFFICIENCY (GROUND) HIGH IMPROVING
SAFETY Keep aircraft out of beam Safe
PERCEPTION Public fears of “cooking” Government fears of
“weapons”

8. WPT USING MICROWAVES
 Typical WPT uses point-to-point power transmission.
 Lower frequency electromagnetic waves suffer from
directivity issues and less efficiency.
 The Rayleigh criterion dictates that any radio wave,
microwave or laser beam will spread and become weaker
and diffuse over distance;
 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.

9. WPT USING MICROWAVES(Continued)
 Microwaves have frequencies between 300 MHz
(0.3 GHz) and 300 GHz (1m to 1mm).
 The atmosphere is transparent at longer
wavelengths (e.g. 100 MHz), opaque at shorter
wavelengths (e.g. 400 GHz), but becomes
transparent again when you go up to 500 THz
(light).

10. WINDOWS

11. BUILDING BLOCKS OF MWPT SYSTEM
 A converter for converting DC to Microwave
frequency.
 Antenna for transmission of the generated
microwave.
 A rectifying antenna (RECTENNA) for receiving the
microwave beam and converting back into DC.

12. BLOCK DIAGRAM OF MWPT SYSTEM

13. DC-RF (MICROWAVE GENERATOR)
The DC-RF conversion is done , using MAGNETRONS.
www.smarttech.com

14. RF-DC CONVERSION(RECTENNA)
 RECTENNA- Rectifying Antenna
 Invented in 1964 and patented in 1969 by William C. Brown.
 Its a special type of antenna used to convert microwave energy
into DC.
 The simplest crystal radio receiver, employing an antenna and
a demodulating diode (rectifier), is actually a rectenna -
although it discards the DC component
 A simple rectenna element consists of a dipole antenna with
an RF diode connected across the dipole elements.
 The diode rectifies the AC current induced in the antenna by
the microwaves, to produce DC power, which powers a load
connected across the diode.

15. SCHEMATIC DIAGRAM

16. MICROSTRIP RECTENNA
www.smartmatech.com
• The diagram
shows a micro
strip rectenna
•A large
rectenna
consists of
array of many
such dipole
elements.

17. SOLAR POWER SATELLITE
A CONCEPTUAL VIEW OF THE SYSTEM
www.pedain.com

18. SPACE ANTENNA
The effective aperture size of Tx
can found out using the formula:
Assuming that transmitter
aperture efficiency is 80%, the
actual physical size of Tx is
found using:
Reference [1]

19. SPACE ANTENNA(Continued)
 It is composed of pilot signal receiving antennas
followed by detectors finding out the location of the
rectenna on the earth, power transmission antenna
elements.
 The pilot signal frequency and a frequency for the
energy transmission are different from each other
( otherwise they will interfere each other).
 Pilot signal makes it possible to find out the accurate
direction of a specified rectenna.

20. GROUND RECTENNA FOR SPS SYSTEM
www.airspacemag.com

21. NEEP602 Course Notes (Fall 1997) Resources from Space

22. EFFICIENCY
 Received power at rectenna, given by Friis
transmission equation:
where Gt and Gr are the antenna gains (with respect to
an isotropic radiator) of the transmitting and receiving
antennas respectively, and R is the distance between the
antennas.

23. TEST RESULT (R=225Km,Pt=1kw)
Gr f(GHz) Gt Pr(microwatt)
40 dB 5.8 20dB 0.3347
5.8 30dB 3.3466
10 20dB 0.1126
10 30dB 1.1258
50dB 5.8 20dB 3.346
5.8 30dB 33.4660
10 20dB 1.125
10 30dB 11.2580

24. CONCLUSION
 The system efficiency is very low to be used for
practical purpose with current technology.
 Emergence of META MATERIALS may change the
scenario in future.
 Metamaterial antennas use metamaterials to
increase performance of miniaturized (electrically
small) antenna systems.

25. REFERENCE
1. Corey Bergsrud, Sima Noghanian, Jeremy Straub, David
whalen, Ronald Fevig “ORBIT-TO-
GROUND WIRELESS POWER TRANSFER TEST
MISSION”, 2013 IEEE
2. Syed Atif Adnan, Muhammad Inam Abbasi, Farukh
Kamran
“WIRELESS POWER TRANSFER USING MICROWAVES
AT 2.45 GHz ISM BAND”, proceedings of international
Bhurban Conference on applied science and technology,
Islamabad, Pakistan
3. T.S. Hasaramani
“WIRELESS POWER TRANSFER FOR SOLAR POWER
SATELLITE” , AKGEC journal of technology, vol .1 , no.2

26. *******THANK YOU******