87205 - Technologies and Applications of Wireless Power Tranfer M

Learning outcomes

The course aims at providing the rules for the analysis and design of a wireless link for the transmission of RF electromagnetic energy, exploiting both radiative techniques, by means of active antennas at the transmitter side and rectenna (rectifying antennas) at the receiver side, and non-radiative ones by inductive and capacitive coupling.The main non-linearities responsible for energy conversion, from RF to dc and vice versa, is studied and CAD tools based on the harmonic balancing technique are studied.The design process is also experimented by means of real-life systems based on simple energy reception systems for both radiation and reactive coupling mechanisms.

Course contents

Functional blocks of radiofrequency (RF) wireless systems and main nonlinearities of their operating functions, and tools for their analysis and design.

Analytical methods for the characterization of nonlinearities in sinusoidal and multi-tone regime: frequencies generation, saturation, AM-PM conversion, frequency conversion, and nonlinear distortion.

Circuit model of nonlinear devices for power generation (transmitter side) and for RF-dc conversion (receiver side): MESFET and DIODES.

Harmonic Balance method and introduction to commercial simulation tools for RF circuit analysis/design. Hints on electromagnetic software tools. Main network functions definition for circuital performance evaluation of RF systems. In particular, the efficiency of an entire link for Wireless Power Transfer (WPT) is considered, and its different contributions are described from both a circuital and a systemistic point of view. Analyis and design of WPT subsystems both radiative (far-field) and non-radiative (near-field)

Near-field techniques

Inductive and capacitive couplings: design of the wireless link and efficiency definition

Electromagnetic modelling of coils and corresponding analysis of the performance

Scheme and design of the transmitter and the receiver

Far-field techniques

Energy harvesting from environmental sources and intentional wireless power transmission

Main characteristics of the antennas to be adopted

Possible schemes for the receiving power systems. Different rectenna (rectifying antenna) topologies

The final part of the course is devoted to the study of:

- some systems for near-field power transfer for wearable or implantable devices

- Rectennas for wide-band energy harvesting from the environment (far-field)

Readings/Bibliography

• D. Pozar, Microwave engineering, 4th Edition, Wiley

• Slide delle lezioni

• Articoli selezionati tratti dalla letteratura specializzata

• "Wireless Power Transfer - Principles and Engineering Exploration", Ki Young Kim, InTech

Teaching methods

Lectures with slides

- There will also be: i) some intermediate test activities (not subject to evaluation); ii) some laboratory classes for electromagnetic/circuit simulation training for the creation of simple models for rectennas characterization

Assessment methods

Oral exam on both theoretical and laboratory parts

Teaching tools

During the study of the theoretical part, the lecturers will continuously refer to and bring in class RF subsystems developed durign their research activity (with special emphasis on energy harvesting and WPT systems)

Office hours

See the website of Alessandra Costanzo