Ing Ind - Inf (Mag.)(ord. 270) - MI (476) ELECTRONICS ENGINEERING - INGEGNERIA ELETTRONICA
095251 - SIGNAL RECOVERY
The course is intended not just to lead students to know and properly describe the electronic techniques and instrumentation developed for recovering sensor signals from noise, but rather to gain a good insight in the problems faced and the approaches developed to overcome them. This implies to critically evaluate the solutions, avoiding the attitude where sensors and electronics are designed and employed just according to the established rules and standards. It is instead necessary to clarify the reasons of the choices and decisions in the light of the physics of phenomena involved, of the basic principles of signal and noise processing and of the actual performance of the available devices. It is necessary to clearly distinguish the intrinsic limitations set by physical laws from the current limitations set by the state of the art, which can be overcome by the technological progress. In essence, to gain insight means to progress at the pace of the technology evolution and be able to contribute to it.
Risultati di apprendimento attesi
Expected learning outcomes
Knowledge and understanding
Students will learn how to:
comprehensively understand the principles of signal and noise filtering
Identify the theoretical best filters
Understand the working principle of the most common filters
Understand and manage the issues related to the 1/f noise
Have a basic knowledge of the physics of photodiodes, phototube, strain gauges and temperature sensors
Applying knowledge and understanding
Given specific project cases, students will be able to:
Apply appropriate techniques in the design of different types of filter to meet given specification
Select sensors and front-end electronics suitable for the specific application
Perform the calculation of the obtainable signal to noise ratio
Analyze and comment on specific architectural choices
Apply the theory to assess the availability of a best filter
Signals and noise. Introduction to measurements, errors and statistical distributions. Mathematical treatment of signals and noise in the time and in the frequency domain. Signal-to-Noise ratio (S/N). Autocorrelation functions, energy and power spectra. Noise sources in electronic circuits and sensors. Main types of noise spectra. Noise interpretation and modeling with statistical pulse sequences.
Extracting signals from noise. Linear filters with constant parameters and with time-variant parameters, action on signals and noise and resultant S/N. Pulse-signals and constant-parameter low-pass filters; Gated Integrator (GI); Boxcar Integrator (BI); Sample-and-Hold (S&H) and fast samplers; discrete filtering by sampling and weighted average of samples. Optimum filtering for pulse-amplitude measurements, significance and practical usefulness. Noise with 1/f spectrum: characteristic features and ensuing problems, filtering approach. Constant-parameter high-pass filters; correlated double sampling (CDS) and further developments; Baseline Restorer (BLR). Periodic signals and constant-parameter resonant filters; modulation of signals and noise; Lock-in Amplifier (LIA), analog and digital implementations of LIAs.
Sensors are treated by discussing the physical principles of their operation; the device structure and technology; characteristic features and electrical parameters; output signals and information content; equivalent electric circuit; internal noise. Photodetectors: vacuum tube and semiconductor photodiodes; photoconductors; Photomultiplier tubes (PMT), avalanche photodiodes (APD) and single-photon avalanche diodes (SPAD); analog and digital detection, single-photon counting (SPC) and time-correlated single-photon counting (TCSPC). Temperature Sensors: thermocouples and thermo resistances; semiconductor junction sensors. Strain and Force Sensors: strain gauges and piezoelectric sensors.
Foundations of electronic circuits and semiconductor devices. Foundations of signals and transmission. Basic knowledge of probability and statistics. General background in mathematics and physics.
Modalità di valutazione
Assessment will be based on a final exam consisting of a 2-hours, closed-book written exam, typically including two problems related to practical applications and theoretical questions.
Students who pass the written exam with a score above 26/30 may take an optional oral exam to adjust the final grade. The oral exam has no positive or negative limits in the adjustment of the written exam result.
Type of assessment
Solution of numerical problems
Computation of signal to noise ratio in the particular application
Minimum detectable signal estimation
Sensor performances calculation
Exercises focusing on design aspects
Selection and design of filters for the specific applications
Definition of minimum required performance of specific kind of sensor
Open-answer theoretical/practical questions on any topic of the course.
Theoretical/practical questions drawn from any topic of the course.
Complete set of slides employed in the lectures; Text and explanation of problems given in the written tests carried out in previous years; Papers, presentations, technical documentation, suggested references and websites dealing with signal recovery, sensors and measurement instrumentation
Sergio Cova, Notes and Bibliography for the course "Signal recovery", Editore: Libreria Cortina, Anno edizione: 2014
T.H. Wilmshurst, Signal recovery from noise in electronic instrumentation, 2nd edition, Editore: A. Hilger - IOP Publishing Ltd, Anno edizione: 1990, ISBN: 0-7503-0058-2
Silvano Donati, Photodetectors: Devices, Circuits and Applications, Editore: Prentice Hall, Anno edizione: 2000, ISBN: 0130203378
Tipo Forma Didattica
Ore di attività svolte in aula
Ore di studio autonome
Laboratorio Di Progetto
Informazioni in lingua inglese a supporto dell'internazionalizzazione
Insegnamento erogato in lingua
Disponibilità di materiale didattico/slides in lingua inglese
Disponibilità di libri di testo/bibliografia in lingua inglese
Possibilità di sostenere l'esame in lingua inglese
Disponibilità di supporto didattico in lingua inglese