wireless power transfer system and wireless energy harvesting

2.  Wireless energy harvesting (EH) is a promising solution
to prolong lifetime of power-constrained networks such
as biomedical implants and sensor networks & IoT.
 Beamforming WPT systems either operate in an open
loop way or use channel sensing methods for closed loop
optimization.
 They have lower end-to-end efficiency, have large size
and weight, and incur high cost.
 The propose of this project to develop a ULP received
power sensing technique and backscattering
communication method with closed loop beamforming.
 Propose method is maximize the RF energy, increase the
efficiency, lower the cost and size

3.  This new green communication technique provides a
promising solution for prolonging the lifetime of energy-
constrained communication networks such as military
communications, sensor networks , submarines, and
medical implants.
 Many types of EH schemes according to the energy
source have been considered, like solar, piezoelectric,
wind, hydroelectric, and wireless radio frequency (RF)
signals.
 Both stability and the availability of wireless signals (TV
broadcasting, mobile base stations, etc...) nominate
wireless EH (the ability of transforming the wireless RF
signals into DC voltage to charge the device battery) as
the best EH scheme.

4.  Any radio transmitting device can be considered as a
source for wireless energy harvesting. The frequency
range and operating power depend on the specific
application of the transmitter.
 The most common radio wave sources are mobile base
stations, radio broadcasting stations, TV broadcasting,
satellites, wireless LAN transmitters (Wi-Fi), and mobile
devices.

5.  Battery-less power source
 Biomedical implants and devices
 Smart switches for home automation
 Internet of Things applications
 Recharging of devices
 Power source for smart sensors
 Simple design and cost-effective
 Easier implementation

6.  Conventional power sources can be replaced
 Unlimited spectrum of sources
 Efficient source of energy
 No wastage, green energy
 No need for periodic replacement of the battery
 Extended life for devices due to recharging of storage
battery during sleep mode

7.  Continuous power supply for IoT devices.
 Beamforming WPT system either operate in an open loop
way or use channel sensing methods for closed loop
optimization
 Lower end-to-end efficiency
 Large size and weight and incur high cost
 The energy in RF waves is very weak. It is only a tiny
fraction of the energy in an electrical current. This makes
it difficult to capture the energy and convert it into useful
power.
 The energy in RF waves is spread out over a wide range
of frequencies. This makes it difficult to isolate the
energy and convert it into useful power.

8.  The energy in RF waves is often intermittent. This makes
it difficult to capture the energy and convert it into useful
power.

11. 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4
Time 10
-8
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
Amplitude
Transmitter output

12. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Time 10
-6
0
0.5
1
1.5
2
2.5
Amplitude
RF2DC output

13. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Time 10
-6
0
20
40
60
80
100
120
140
160
Amplitude
Backscatter Input

14. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Time 10
-6
0
0.005
0.01
0.015
0.02
0.025
0.03
Amplitude
Backscatter output

15.  RF energy harvesting is limited by the amount of power
that can be transmitted by the radio waves.
 The efficiency of RF energy harvesting is also limited by
the distance between the transmitter and receiver. The
further the distance, the less power is received by the
receiver.
 Wireless energy harvesting has a lot of limitations due to
its dependency on external sources which are prone to
atmospheric changes, physical obstacles, and radio wave
source uptime. Received power from the sources is too
low and the level often varies in time.

16.  System efficiency is reduced over time due to the
performance of the components used in the devices like
capacitors, diodes, backup storage battery, etc.… The
design of receivers in a wide frequency range is often
challenging, a device designed to operate at one
frequency band is limited only on that spectrum.

17.  The correct phase and frequency offset among energy
transmitter for optimal beamforming to maximize energy
transfer.
 The proposed rectifier topology for RF to DC conversion
with a maximum power tracking technique have
maximum efficiency 40-70%.
 From Backscattering technique to ensure the most of the
incoming energy goes towards harvesting.

18.  In conclusion, emerging technologies like the Internet of
Things will require an efficient energy source to connect
billions of smart devices and sensors for a wide spectrum
of applications.
 Long-term sustainable and reliable energy sources are
inevitable for any efficient system.
 Wireless energy harvesting is an area for future
developments to deliver effective solutions for IoT,
medical, industrial, and other smart home applications.

19.  X. Lu, P. Wang, D. Niyato, D. I. Kim and Z. Han, "Wireless Networks With RF
Energy Harvesting: A Contemporary Survey," IEEE Communications Surveys &
Tutorials, vol. 17, no. 2, pp. 757-789, Secondquarter 2015, doi:
10.1109/COMST.2014.2368999.
 S. Timotheou, I. Krikidis, G. Zheng and B. Ottersten, "Beamforming for MISO
Interference Channels with QoS and RF Energy Transfer," IEEE Transactions on
Wireless Communications, vol. 13, no. 5, pp. 2646-2658, May 2014, doi:
10.1109/TWC.2014.032514.131199.
 Y. Zeng and R. Zhang, "Optimized Training Design for Wireless Energy Transfer,"
IEEE Transactions on Communications, vol. 63, no. 2, pp. 536-550, Feb. 2015, doi:
10.1109/TCOMM.2014.2385077.
 X. Chen, C. Yuen and Z. Zhang, "Wireless Energy and Information Transfer
Tradeoff for Limited-Feedback Multiantenna Systems With Energy Beamforming,"
IEEE Transactions on Vehicular Technology, vol. 63, no. 1, pp. 407-412, Jan. 2014,
doi: 10.1109/TVT.2013.2274800.
 F. Quitin, U. Madhow, M. M. U. Rahman and R. Mudumbai, "Demonstrating
distributed transmit beamforming with software-defined radios," IEEE
International Symposium on a World of Wireless, Mobile and Multimedia Networks
(WoWMoM), San Francisco, CA, 2012, pp. 1-3, doi:
10.1109/WoWMoM.2012.6263729.

20. THANK YOU