Towards the future wireless networks, RF - energy harvesting is a key enabler for a truly wireless devices, all the time. Enjoy .. :)

1. RF – Energy Harvesting
By: Belal Essam
8 January 2017

2. Agenda
• Conventional Powered Communication Networks.
• Naturally Powered Communication Networks (Energy Harvesting).
• Wireless Power Transfer, The Early Trials.
• Wireless Powered Communication Networks (RF-Energy Harvesting).
• Research directions in RF-Energy Harvesting.
• Wireless Powered Communication Networks Applications.
8 January 2017

3. Conventional Powered Communication
Networks
• Need manual battery recharging/replacement.
• Inapplicable in some scenarios
• Body sensors,
• sensors in dangerous environment (Volcanos, …
etc.)
• Costly inefficient.
8 January 2017
Source: Rui Zhang “Wireless Powered
Communication Networks: An Overview”,
WCNC , April 2016.

4. Naturally Powered Communication Networks
(Energy Harvesting)
• Energy source (renewable)
• Sun, Wind, …, etc.
• Costly inefficient.
• Bulky (big size).
• Not on-demand (uncontrollable).
8 January 2017
Source: Rui Zhang “Wireless Powered
Communication Networks: An Overview”,
WCNC , April 2016.

5. Wireless Power Transfer, The Early Trials
• “Wardenclyffe Tower”, also known as (aka) the “Tesla Tower”.
• A Wireless transmission station designed and built by Nikola Tesla in New York in 1901.
• Tesla intended to transmit messages, telephony and even facsimile images across the
Atlantic to England and to ships at sea.
• Intended for wireless power transfer at 150 KHz and 300 kW, un-succeeded and never
put in practice.
• Additional investment could not be found and the project was abandoned in 1906 and
never became operational.
8 January 2017

6. Wireless Powered Communication Networks
(RF-Energy Harvesting)
• Small size receivers.
• On-demand charging (controllable).
• Cost efficient.
• Low efficiency, but Still under
development.
• Reported that 3.5mW and 1uW of
wireless power can be harvested from RF
signals at distances of 0.6 and 11 meters,
respectively, using Powercast RF energy
harvester operating at 915MHz.
8 January 2017
Source: Rui Zhang “Wireless Powered
Communication Networks: An Overview”,
WCNC , April 2016.

7. Research directions in RF-Energy Harvesting
• Prototyping receiver architecture.
• Wireless energy transfer source.
• Different network architectures.
• Optimal resource allocation (time,
frequency, power, …, etc.)
• Information/Energy mode exchange.
8 January 2017

8. Wireless energy transfer source
• Moving vehicles.
• Dedicated power beacons.
• Hybrid Access Points.
8 January 2017
Source: Rui Zhang
“Wireless Powered
Communication
Networks: An Overview”,
WCNC , April 2016.
Source: E. Hossain,
et al., "Wireless-
powered cellular
networks: key
challenges and
solution
techniques," in
IEEE Comm. Mag.
June 2015.

9. Information/Energy mode exchange
• Time switching receiver.
• Power splitting receiver.
• Antenna switching receiver.
8 January 2017
Source: Rui Zhang
“Wireless
Powered
Communication
Networks: An
Overview”,
WCNC , April
2016.

10. Wireless Powered Communication Networks
Applications
• Wireless Powered Cognitive Radio Network.
• Conventional network: SU is silent during PU transmission.
• Wireless powered network: SU harvests energy during PU transmission.
8 January 2017
Source: Rui Zhang
“Wireless Powered
Communication
Networks: An
Overview”,
WCNC , April 2016.

11. Wireless Powered Communication Networks
Applications
• Different receivers sensitivities enable the design of such a network.
• Information decoding Rx: -60 dBm.
• Energy harvesting Rx: -10 dBm.
8 January 2017
Source: Rui Zhang
“Wireless Powered
Communication
Networks: An Overview”,
WCNC , April 2016.

12. References
• Rui Zhang “Wireless Powered Communication Networks: An Overview”, WCNC ,
April 2016.
• H. Tabassum, E. Hossain, A. Ogundipe and D. I. Kim, "Wireless-powered cellular
networks: key challenges and solution techniques," in IEEE Communications
Magazine, vol. 53, no. 6, pp. 63-71, June 2015.
• A. M. Zungeru, L. M. Ang, S. Prabaharan, and K. P. Seng, “Radio frequency energy
harvesting and management for wireless sensor networks,” Green Mobile
Devices and Netw.: Energy Opt. Scav. Tech., CRC Press, pp. 341-368, 2012.
8 January 2017

13. 8 January 2017