High-Efficiency Wireless Power Transmission for Portable Electronic Devices

2017 ELE Engineering Design Project (FY04)

Faculty Lab Coordinator

Fei Yuan

Topic Category

Intelligent Instrumentation


Wireless power transmission is critically needed in applications where interconnecting wires are inconvenient, hazardous, or impossible. Wireless power transmission has found a broad range of emerging applications from small electronic devices such as powering implanted sensors, embedded sensors, radio-frequency identification tags, small appliances such as wireless cellphone chargers, wireless toothbrush chargers to electric devices such as induction cookers and electric vehicles. Electrodynamic induction wireless transmission technique that is widely used for these applications uses near-field magnetic coupling over distances up to about one-sixth of the wavelength. Electric current flowing through a primary coil creates a magnetic field that acts on a secondary coil producing a current within it. Coupling must be tight in order to achieve high efficiency. Resonant coupling where transmitter and receiver inductors are tuned to the same frequency increases the transmission range. Performance can be further improved by modifying the drive current from a sinusoidal to a non-sinusoidal transient waveform. This project designs a wireless power transmission system with the emphasis on the automatic tuning of the receiver and electrical signaling to achieve the maximum power transmission efficiency.


Design a high-efficiency wireless charging station for portable electronic devices.

Partial Specifications

1) Power harvester to convert the energy of incoming AC power to a stable DC power with a low-voltage drop (LDO) in case of a varying load.
2) Automatically tuning of power harvester’s resonant frequency to maximize power transmission efficiency
3) Investigate signaling for maximum power transmission.

Suggested Approach

1) Identify an application and establish the overall design specifications.
2) Study current standards on wireless power transmission.
3) Study the fundamental of wireless AC power transmission, especially resonance-based wireless power transmission.
4) Develop the architecture of the system and the specifications of the building blocks of the system.
5) Carry out detailed circuit design of all building blocks and conduct extensive simulation to ensure that the performance of the building blocks meet the design specifications.
5) Build the entire power transmission system using discrete components.

Group Responsibilities

Define the overall specifications of each building block of the system. The group members of the project will work as a team to undertake this challenging project. A full corporation is needed to ensure the progress and completion of the project.

Student A Responsibilities

The student is responsible for the design of the transmitter for wireless power transmission. The transmitter consists of an oscillator that generates a square wave to modulate the downstream power amplifier, a drive that takes the output of the oscillator as its input and output a square wave with a large driving capability, a power amplifier that outputs a sinusoidal wave with a large current to the load coil, and an automatic tuning circuit that maximizes the amount of power delivered to the load coil. power harvester that includes matching transformer for amplitude boosting, rectifiers for ac-dc conversion, and voltage regulator with a low-voltage drop.

Student B Responsibilities

The student is responsible for the design of the receiving coil of the receiver, a rectifier that performs AC-to-DC conversion, a voltage regulator with a low-voltage drop that maintains a constant output voltage when load varies, and an automatic detection circuitry that detects whether the efficiency of the receiver is at its maximum or not.

Student C Responsibilities

The student is responsible for detecting whether the position of the portable electronic device is the optimal or not. If it is placed at a non-optimal location, the system should be able to detect this and display an alerting message on the screen of the portable electronic device so that the user can change the location so as to obtain the best charging efficiency.

Course Co-requisites



FY04: High-Efficiency Wireless Power Transmission for Portable Electronic Devices | Fei Yuan | Saturday September 16th 2017 at 05:37 PM