Wireless Power
How it works
Disclaimer: The purpose of this information is
to explain the wireless power technology – It
can differ in some aspects from the
specification.
Target
• Main application
– Battery charging, or other suitable loads
– For wide range of mobile devices
• Mobile phone, camera, mp3 player, headset, …
• Up to 5W of power delivery
– More power at later versions
• Power transfer via magnetic induction
– Loosely coupled transformer
– At short distance (few mm)
2
dB/dt
I
Base Station
Transmitter
Transmitter
System Overview (Top View)
• Base Station
– Contains one, or more transmitters
– Transmitter provides power to receiver
• Mobile Device
– Contains a receiver that provides power to a load (e.g. a battery)
– Receiver provides control information to transmitter
3
Mobile Device
Receiver
Transmitter
Load
System
Power
Control
Base Station
Transmitter
Transmitter
System Overview (Power
Conversion)
• Power Conversion Unit converts electrical power to
wireless power signal
• Power Pickup Unit converts wireless power signal to
electrical power
4
Mobile Device
Receiver
Transmitter
Load
System
Power
Power Conversion Power Pick-up
Control
Base Station
Transmitter
Transmitter
System Overview (Control)
• Receiver controls the power to the output load
– To the need of the mobile device (required power)
– To the desired operation point (e.g. output current, voltage)
• Transmitter adapts power transfer
– To the need of the receiver (required power)
– To the desired operation point (e.g. primary coil current)
5
Mobile Device
Receiver
Transmitter
Load
System
Power
Power Conversion Power Pick-up
Control
Control
Control
