35112 - Autonomous RF Sistems (2nd Cycle)

Learning outcomes

At the end of the course, the student knows the tools necessary for the analysis and design of the circuits and subsystems that make up the RF and microwave front-ends. He also knows the non-linearities that underlie their operation and the CAD tools that allow them to be accurately characterized. Finally, the student has knowledge of the methods for realizing the energy autonomy of the front-ends by exploiting the received radio waves and the relative environmental advantages due to the absence of batteries. The student also knows the applications in the field of RF and microwave identification (RFID) and in the field of sensor networks for environmental 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 hravesting from the environment (far-field)

Teaching methods

Lectures based on text book and selected papers, individual homework assignments and a design project. In the project students must design a WPT system with given properties. The System should be modelled, simulated, analyzed and measured.

Assessment methods

team working project and oral exam

Office hours

See the website of Alessandra Costanzo

See the website of Francesca Benassi