35112 - Autonomous RF Sistems (2nd Cycle)

Learning outcomes

At the end of the course, the student knows the tools for the analysis and design of circuits and subsystems representing the building blocks of RF and microwave front-ends. She/he will also know the nonlinear effects at the base of front-end operation and the CAD tools to accurately take them into account during front-end design. The student learns the methods to achieve front-end energy autonomy through the exploitation of received radio waves, therefore avoiding the use of batteries, with great advantages for the environmental impact. The student will also acquire knowledge of possible applications in the field of RF and microwave identification (RFID) and RFID-enabled sensors for environment control.

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

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

Office hours

See the website of Alessandra Costanzo