RF Energy Harvesting

Team 2
AFRL WSN Health Diagnostic
What is energy harvesting?
The process by which energy is derived from
external sources
Why use energy harvesting?
 Renewable source
 Allows for remote charging in applications
Energy harvesters provide a very small amount
of power for low-energy electronics
 The energy source for energy harvesters is
present as ambient background and is free
 As opposed to large-scale energy
generation which costs money
Converted energy can be stored in a
capacitor for short-term use or a battery
for long-term use.
Allows for the battery (or a charger) to be
taken out of the equation of an application
since it sources energy from the
 Piezoelectric
 Pyroelectric
 Photovolatics
 Kinetic Energy
 RF Energy
Converts mechanical
strain to electric
Produces power on
the order of mW
Useful for small
 Handheld devices
 Light bulbs
Human Motion
Acoustic Noise
Converts changes in
temperatures to electric
Stable for temperatures
above 1200 ⁰C
High thermodynamic
Used in
 Power Plants
 Automobiles
Converts human and/or natural
motion into electric current
Found in
 Wind Turbines
 Ocean Wave Buoys
 Human Motion
Also known as solar
 Converts solar
radiation into DC
 Found just about
everywhere and
gaining more
Converts RF signal energy into DC power
RF energy is available in a wide array of frequency
bands due to everyday technologies
 Cell Phones
 Radio Towers
 WiFi Routers
 Laptops
 TV Signals
Only a tiny amount of power can be harvested, good for
low power applications (Ex: A WiFi router can transmit
Usually very short distance, however Powercast
demonstrated energy harvesting at 1.5 miles
Our project uses RF power harvesting
Ultra-low power, battery free applications
 Perfect for wireless sensor networks
Intentional Sources
 Powercast utilizes a direct RF energy
source, dedicated to providing RF energy
for harvesting
Anticipated Ambient Sources
 Routers, cell phone transmitters
Unknown Ambient Sources
 Microwave radio links, mobile radios
Module Components & Features
Powercast P2110 Powerharvester™ Receiver
MCU: Microchip PIC24 XLP
Radio module
Microchip MRF24 (802.15.4)
 RF Powerharvester
 System power: 3.3V
 Capacitor
50mF (as low as 3300uF)
Discrete sensors: Temp, Humidity, Light
Wireless protocol: MiWi™ P2P
Center Frequency = 915MHz
Intentional RF Source
Directional Antenna
Optimized RF Powerharvesting for the
transmitter frequency
RF Powerharvesting allows for remote
placement of sensor nodes
Great performance due to a design that
focuses on minimizing power
consumption in each node
 Proprietary wireless protocol
Power harvesting technologies are
everywhere and efficiencies are vastly
 Simply look at solar efficiencies
Most of the world’s energy in the future
will be generated using power harvesting
Related flashcards

Sailing ships

48 cards

Renewable energy

40 cards

Gasoline engines

18 cards

Gasoline engines

22 cards

Create Flashcards