32 citations · 87 across the 11 of their papers we have counts for
6 papers · 1 filter
From Chirps to Random-FM Excitations in Pulse Compression Ultrasound Systems
Sergio Callegari, Marco Ricci, Salvatore Caporale +6
Pulse compression is often practiced in ultrasound Non Destructive Testing (NDT) systems using chirps. However, chirps are inadequate for setups where multiple probes need to opera…
Sample and Hold Errors in the Implementation of Chaotic Maps
Sergio Callegari, Riccardo Rovatti
Though considerable effort has recently been devoted to hardware realization of chaotic maps, the analysis generally neglects the influence of implementation inaccuracies. Here we…
Noise Weighting in the Design of ΔΣ Modulators (with a Psychoacoustic Coder as an Example)
Sergio Callegari, Federico Bizzarri
A design flow for ΔΣ modulators is illustrated, allowing quantization noise to be shaped according to an arbitrary weighting profile. Being based on FIR NTFs, possibly with high or…
Should ΔΣ Modulators Used in AC Motor Drives be Adapted to the Mechanical Load of the Motor?
Sergio Callegari, Federico Bizzarri
We consider the use of ΔΣ modulators in ac motor drives, focusing on the many additional degrees of freedom that this option offers over Pulse Width Modulation (PWM). Following som…
Output Filter Aware Optimization of the Noise Shaping Properties of ΔΣ Modulators via Semi-Definite Programming
Sergio Callegari, Federico Bizzarri
The Noise Transfer Function (NTF) of ΔΣ modulators is typically designed after the features of the input signal. We suggest that in many applications, and notably those involving D…
A CMOS Tailed Tent Map for the Generation of Uniformly Distributed Chaotic Sequences
Sergio Callegari, Gianluca Setti, Peter J. Langlois
This paper describes the design of a modified tent map characterized by a uniform probability density function. The use of this map is proposed as an alternative to the tent map an…