UNIVERSITA’ DEGLI STUDI DI ROMA TOR VERGATA
Dipartimento di Ingegneria Elettronica
Research topics
1. Analysis and Design of High Power Amplifiers
P. Colantonio, F. Giannini
Collaborations: Chalmers University (Swedish), Universidad de Cantabria (Spain), Universidad de Malaga (Spain), Donetsk National University (Ukraine), Tomsk State University of Control Systems and Radioelectronics (TUCSR, Russia), Ericsson AB (Swedish), Erzia (Spain), TTI (Spain), Politecnico di Torino, Università di Bologna, Università di Firenze, Università di L’Aquila, Università di Ferrara, Selex-SI, Elettronica Spa, Thale Italia Space, Space Engineering
2. High Performance Receiving Subsystems
E. Limiti
Collaborations: Thales Alenia Space Italy, IRA-INAF, ASTRON, Jodrell Bank Observatory, MPIfR
3. Development of circuital models and design procedures for microwave and millimeter waves MEMS components
G. Bartolucci
Collaborations: Istituto per la Microelettronica e Microsistemi CNR
4. Characterization, modelling and applications of piezoresistive sensors for human body movement tracking
F. Giannini, G. Orengo
Collaborations: ASI-Agenzia Spaziale Italiana, ISPESL-Istituto Superiore per la Prevenzione e la Sicurezza sul Lavoro
5. Organic semiconductor devices and nanostructures
A. Di Carlo, A. Reale, F. Brunetti
Collaborations: CNR, SELEX-SI, Regione Lazio, TUM, SELEX-GALILEO, ERG, PERMASTEELISA, FP7 Project “HYMEC”, FP7 Project “OPTHER”
6. Modeling and experimental study of nanostructured devices
A. D. Carlo, A. Reale
Collaborations: European Network ``CLERMONT IV'', FP7-STREP "SMASH", SELEX-SI, ESA
7. Micro-nano-systems for energy harvesting and medical applications
C. Falconi, A. D’Amico
Collaborations: Rodolfo Araneo, Aldo Di Carlo, Andrea Notargiacomo, Antonio Rinaldi, Zhong Lin Wang
8. Sistemi sensoriali ed applicazioni in campo medico e spaziale
A. D’Amico, C. di Natale, M. Santonico, E. Martinelli.
Collaborations: Università Campus Biomedico di Roma: G.Pennazza: Dip. Scienze e Tecnologie Chimiche Tor Vergata: prof.R.Paolesse.
9. ALGORITHMS AND VLSI ARCHITECTURES FOR DIGITAL SIGNAL PROCESSING
G. C. Cardarilli
Collaborations: Thales Alenia Spazio, Selex S.I., Elettronica S.p.A., Centro Vito Volterra
10. Design of Low-Power Systems for DSP
G. C. Cardarilli, M. Re
Collaborations: DTU Copenhagen
11. Reconfigurable processors for DSP
G. C. Cardarilli, M. Re
Collaborations: Princeton University, Thales Alenia Space, DTU Copenhagen, Elettronica S.p.A.
12. DSP PROCESSORS FOR HUMAN-MACHINE INTERFACES
G. C. Cardarilli, M. Re
Collaborations: Dip. Neurofisiopatologia, SkyTechnology, Santa Lucia
Analysis and Design of High Power Amplifiers
P. Colantonio, F. Giannini
Collaborations: Chalmers University (Swedish), Universidad de Cantabria (Spain), Universidad de Malaga (Spain), Donetsk National University (Ukraine), Tomsk State University of Control Systems and Radioelectronics (TUCSR, Russia), Ericsson AB (Swedish), Erzia (Spain), TTI (Spain), Politecnico di Torino, Università di Bologna, Università di Firenze, Università di L’Aquila, Università di Ferrara, Selex-SI, Elettronica Spa, Thale Italia Space, Space Engineering
The research activity is focused on the identification of high efficiency (and compatibly low distortion) power amplifier design strategies for radar, satellite and communication applications.
Different design solutions have been investigated and developed to design high efficiency power amplifiers (PAs) based on harmonic turning strategies and architectures to further increase the average efficiency when complex modulated signals are adopted.
In the former approaches, a major effort from the designer is dedicated to the choice and realization of suitable harmonic terminating schemes, with the general philosophy to minimize the dissipated dc power on the active device while appropriately shaping the current and/or voltage waveforms: in particular, maximum output voltage must occur at low (or zero) current levels and maximum current corresponding at very low voltages.
Different design strategies have been investigated and successfully demonstrated, based on current-mode harmonic tuned design strategies (Class F or in general harmonic tuned), or switched-mode configurations (class E, class F-1, inverse class E, etc.).
Starting from a simplified model for the active device and reviewing the power balance conditions, the PAs design strategies have been identified and classified unifying their theoretical approach.
Closed-form expressions are derived for the major design quantities, together with the optimum fundamental and harmonics loading of the active device.
A comparison is carried out and useful design criteria are inferred for the design of input and output networks of high efficiency/high frequency power amplifiers.
The developed high efficiency design methodologies have been adopted to design several PAs, based on GaAs or GaN devices in both hybrid or monolithic versions.
Moreover, to account for the actual requests for PAs able to operate in different standards and frequency applications, the harmonic tuning strategy has been extended for the design of multi-band PAs.
In this context, it has been developed a theory and the corresponding design relationships to synthesize multi frequency and multi harmonics passive matching networks, aimed to implement the HT strategy realizing concurrent PAs.
Recently, major efforts have been dedicated to the identification of architecture to improve the efficiency performance achievable from a PA involved in systems with high peak-to-average power ratios, as for instance in WCDMA or UMTS applications.
In this case, due to the large input signal dynamic range, even if harmonic tuning design approaches can increase the stand-alone PA performance, it becomes mandatory to operate at a system level also. As a consequence, some "old" solutions have been recently resurrected to overcome the drawbacks related to these kind of signals. In particular, two main strategies have been revisited, namely the Doherty (DPA) and the Envelope Tracking techniques. The former exploit the concept of a dynamic load while the latter of dynamic bias conditions, both with the aim to force the amplifier stage to work at maximum efficiency levels for a predefined input dynamic range.
Regarding the Doherty amplifier, a new simplified theory to analyze its behavior and to infer useful design guidelines have been developed, assuming for the Main amplifier a class AB bias condition, while for the Auxiliary amplifier a Class C bias condition.
The developed theory has been validated throughout the realization of several DPA amplifiers based on GaN.
The DPA synthesis relationships have been further extended to account for different biasing conditions, harmonic tuning strategies and iinovative architecture have been developed and patented.
Publications in 2011
1) L. El Maazouzi, A. Mediavilla, and P. Colantonio, “A contribution to Linearity Improvement of A Highly Efficient PA for WiMAX applications,” Progress In Electromagnetics Research (PIER), Vol. 119, 2011, pp. 59-84 (ISSN: 1070-4698, E-ISSN: 1559-8985).
2) P.Colantonio, F.Giannini, R.Giofrè, L.Piazzon, “Increasing Doherty amplifier average efficiency exploiting device knee voltage behavior,” IEEE Transactions on Microwave Theory and Techniques, Vol. 59, N. 9, Sept. 2011, pp. 2295-2305 (ISSN: 0018-9480, doi: 10.1109/TMTT.2011.2160278).
3) P.Colantonio, F.Giannini, R. Giofrè L. Piazzon, “Experimental Results of An X-Band MMIC Doherty Power Amplifier,” Microwave and Optical Technology Letters, Vol. 53, N. 11, Nov. 2011, pp. 2665-2668 (doi: 10.1002/mop.26306).
4) P. Colantonio, F. Giannini, R. Giofrè, L. Piazzon, “Power Amplifier based on Doherty Power amplifier”, brevetto europeo No PCT/EP2011/060215.
5) P.Colantonio, F.Giannini, R. Giofrè, L. Piazzon, “The weight of the on resistance in Doherty PAs,” Proceedings of the 7th INMMIC Workshop, Wien (Austria), 18-19 April 2011, pp. 1-4.
6) P. Colantonio, F. Giannini, R. Giofrè, L. Piazzon, “Being seventy-five still young: the Doherty Power Amplifier,” Proceedings of 35th Workshop on compound semiconductor device and integrated circuits (WOCSDICE 2011), Catania, Italy May 2011, pp. 3-8 (ISBN: 978-88-8080-123-8).
7) A. Mediavilla, A. Tobia, P. Colantonio, “1 kW Compact L-band Pulsed Power Amplifier for Radar Applications,” 3rd Microwaves, Radar and Remote Sensing Symposium (MRRS-2011), Kiev (Ukraine), 25-27 Aug. 2011, pp. 43-46 (ISBN: 978-1-4244-9643-3, DOI: 10.1109/MRRS.2011.6053597).
8) P. Colantonio, F. Giannini, R. Giofrè, L. Piazzon, “The Doherty amplifier and its evolution for modern communication systems,” 3rd Microwaves, Radar and Remote Sensing Symposium (MRRS-2011), Kiev (Ukraine), 25-27 Aug. 2011, pp. 51-54 (ISBN: 978-1-4244-9643-3, DOI: 10.1109/MRRS.2011.6053599).
9) E. Cipriani, P. Colantonio, F. Giannini, R. Giofrè, “The Switched Approach to RF Power Amplification,” Proceedings of International Symposium on Microwave and Optical Technology, ISMOT 2011, Prague, Czech Republic, June 20-23 2011, pp. 43-46 (ISBN: 978-80-01-04887-0).
10) V. G. Kryzhanovskiy, Yu. V. Rassokhina, P. Colantonio, “The output circuit of inverse class F power amplifier with slot resonators in the microstrip line ground plane,” Proceedings of the 21th International Crimean Conference on Microwave and Telecommunication Technology (CriMiCo), Sevastopol, Ukraine, 12-16 Sept. 2011, pp. 141 - 142 (ISBN: 978-1-4577-0883-1).
11) E. Cipriani, P. Colantonio, F. Di Paolo, F. Giannini, R. Giofrè, R. Diciomma, B. Orobello, M. Papi, “A Highly Efficient Octave Bandwidth High Power Amplifier in GaN Technology,” Proceedings of the European Microwave Integrated Circuits Conference, EuMIC 2011, Manchester, UK, Oct. 2011, pp. 188-191 (ISBN: 978-1-61284-236-3).
12) E. Cipriani, P. Colantonio, F. Giannini, R. Giofrè, “Effects of Gate Bias Voltage and Compression Level on a X-band MMIC Class F-1 PA,” Proceedings of the European Microwave Conference, EUMC 2011, Manchester, UK, Oct. 2011, pp. 546-549 (ISBN: 978-1-61284-236-3).
13) L. Piazzon, P. Colantonio, F. Giannini, R. Giofrè, “New Generation of Multi-Step Doherty Amplifier,” Proceedings of the European Microwave Integrated Circuits Conference, EuMIC 2011, Manchester, UK, Oct. 2011, pp. 116-119 (ISBN: 978-1-61284-236-3).
High Performance Receiving Subsystems
E. Limiti
Several demanding applications require microwave and millimeter-wave receiving front-ends featured by extremely low noise performance. Among them, the focus has been posed on two different areas: receivers for satellite communications and the cryogenic low noise receivers for radio-astronomy applications.
Referring to the former one, high interest is actually in the extension of satellite communication payloads to the millimeter-wave frequency range, where a wider bandwidth is available, bringing in a larger set of potential services and capabilities. To this goal, a primary target consists then in the design and realization of compact and broadband low noise amplifiers, featured by state-of-the art performance. The accomplishment of the given specifications is then realized by using high-performance technologies: in the present case, a 70nm HEMT metamorphic technology has been adopted, featured by monolithic realization of a complete set of passive components. The result has been the design and the realization of amplifying chips featured by 30 dB gain all over the complete Ka Band and over (25-50GHz) with less than 1.5 dB noise figure. The amplifiers are going to be mounted and characterized for on-carrier operation, for subsequent potential use in satellite payloads.
Regarding Radio-astronomy applications, the interest has been posed on the realization, in monolithic form, of an integrated receiver, to form a focal plane array in the focus (primary or secondary one) of large aperture antennas. This approach allows the multi-beam operation and the versatile use both in frequency and pointing of large radio-astronomy antennas. In close cooperation with the Istituto di Radio Astronomia (IRA-INAF), a complete chip-set for signal low noise amplification, amplitude digital control (4 bits/6 bits), phase digital control (6 bits) has been designed realized and tested. The measured results, obtained utilizing OMMIC foundry and covering the 4 - 8 GHz Broadband operation of the single functions demonstrate remarkable performances, consisting in 1 dB noise figure (room temperature, OFB), 30 dB Gain, good i/o matching for the LNA. Buffered attenuation and phase shifting characteristics well agrees with expected performances. All the system components will be cooled to 20 K (LNA) or to 70 K (Phase and amplitude control). The former exhibits, at 25 K room temperature, the remarkable performance of 8 K equivalent noise temperature.
In addition, to move towards higher frequencies and make use of the new facilities that will be available at the radio-astronomy institutes around the world (e.g. the new SRT, Sardinia Radio Telescope), a W band amplifier has been designed and realized, featured by 20 dB gain all over the operating bandwidth (75-110 GHz) and less than 3 dB noise figure at room temperature. Cryogenic (20K) characterization is under way. More recently, as part of the FP7 Project RadioNet, investigations are being carried out regarding high density millimeter-wave multi-pixel cameras operating at cryogenic temperatures (Apricot JRA).
Publications in 2011
1) M.Jankowsky, E.Limiti, D.Palombini, “Q-Band Down-Converting Module for Multi-Pixel Camera Receivers,” Proceedings of the Workshop on Integrated Nonlinear Microwave and Millimetre-wave Circuits (INMMiC Vienna), Vienna, Austria, April 2011, pp.61-64.
2) A.Bentini, B.Pasciuto, W.Ciccognani, E.Limiti, P.Romanini, C.Lanzieri, “C-Band MMIC Chipset and Digital Control Circuits for T/R Modules based on GaAs Enhancement/Depletion Technology,” Proceedings of the 35th Workshop on Compound Semiconductor Devices and Integrated Circuits (WOCSDICE 2011), Catania, Italy, May 29th - June 1st 2011, pp.13-14.
Development of circuital models and design procedures for microwave and millimeter waves MEMS components
G. Bartolucci
The research activities have been essentially focused on the high frequency microelectromechanical system (MEMS) components. More in detail, a first topic of the developed research activity is the mechanical modeling of MEMS capacitive shunt connected devices realized in coplanar waveguide technology.
Another aspect of the microelectromechanical structure behavior which has been investigated is the presence of non linear effects in a typical MEMS element excited by a high power RF signal: an analytic approach quite different from the conventional ones previously proposed in literature has been adopted.
Recently the research activity has been also partially devoted to the development of a novel design procedure for RF MEMS switches. The chosen configuration is composed by two transmission line sections separated a metal membrane providing a shunt connected capacitor. By means of a bias voltage it is possible to actuate the switch and therefore to change the capacitance value. A rigorous analytic circuital model based on the image parameter representation of a two port network has been developed for such a structure. Closed form equations have been presented and design considerations have been discussed. The result is a new methodology for the synthesis of microelectromechanical capacive switches in shunt configuration more general rigorous and efficient than those ones presented in previous papers.
Publications in 2011
1) R. Marcelli, G. Bartolucci, E. Proietti, G. De Angelis, A. Lucibello, F. Giacomozzi and B. Margesin: ”Microwave microsystems: technology and modelling of RF MEMS switches and related applications” in ”Microwave Microsystems”, Editor: G. Schettini, Research Signpost Publisher, 37/661 (2), Fort P.O. Trivandrum-695 023, Kerala, India, India, Chapter No. 7, pp. 181-204, ISBN: 978-81-308-0453-8.
2) G. De Angelis, A.Lucibello, E. Proietti, R. Marcelli, D. Pochesci, G. Bartolucci, M. Dragoman and D. Dragoman: ”Microwave inter-connections and switching by means of carbon nano-tubes”, Nanomater. nanotechnol., 2011, Vol. 1, No. 1, pp. 64-77. ISSN: 1847-9804.
3) S. Simion, G. Bartolucci and R. Marcelli: ”Composite right/left handed based 3-port broadband differential phase shifter”, Proceedings of EuMW 2011, European Microwave Week 2011, 9th - 14th October 2011,Manchester Central, Manchester, UK.
4) R. Marcelli, A. Lucibello, G. De Angelis, E. Proietti, G. Papaioannou, G. Bartolucci, F. Giacomozzi, B. Margesin “Characterization and modeling of charging effects in dielectrics for the actuation of RF MEMS ohmic series and capacitive shunt switches”, InTech Publisher in the on-line Book "Microelectromechanical Systems and Devices", Editor I. Nazmul, University of Texas at Brownsville, USA, ISBN: 978-953-51-0306-6.
5) Romolo Marcelli, Daniele Comastri, Andrea Lucibello, Giorgio De Angelis, Emanuela Proietti, and Giancarlo Bartolucci: “Dynamics of RF micro-mechanical capacitive shunt switches in coplanar waveguide configuration”, InTech Publisher in the on-line Book "Microelectromechanical Systems and Devices", ISBN: 978-953-51-0306-6, Editor I. Nazmul, University of Texas at Brownsville, USA.
6) R. Marcelli, G. Bartolucci, G. De Angelis, A. Lucibello, E. Proietti "Modulation instability in RF MEMS devices", Analog Integrated Circuits and Signal Processing, ISSN 0925-1030, Volume 71, Number 1, DOI 10.1007/s10470-011-9826-z
Characterization, modelling and applications of piezoresistive sensors for human body movement tracking
F. Giannini, G. Orengo
Investigation on the more suitable technologies to register human body movements in 3D space with great spatial accuracy is a very challenging task, because a wide range of applications are concerned, from registration of post-stroke rehabilitation or sports performance, to monitoring of movement of disabled or elderly people, only to give some examples. The possibilities offered by piezoresistive bend sensors applied as wearable devices integrated on body garments are explored. Piezoresistive sensors can be usefully adopted to recover human joint bend angles for body movement tracking. Due to their pliability, sensitivity and cheapness, they could be a valid alternative to movement analysis systems based on optoelectronic devices or inertial electronic sensors. This research suggests a new approach to model their electrical behavior during bending and extension movements, in order to predict their real-time performance during different kind of applications. To simulate the sensor electrical behavior with no mind to its physical characteristics, simple and accurate behavioral models were developed, based on RLC resonant circuits and fitted on the sensor electrical response under fast bending and extension movements. The extracted models are applied to simulate and evaluate the sensor behavior in tracking human movements, such as knee rotations of walkers and runners.
Publications in 2011
1) G.Saggio, S.Bocchetti, C.A.Pinto, G.Orengo, “Electronic Interface and Signal Conditioning Circuitry for Data Glove Systems useful as 3D HMI Tools for Disabled Persons”, International Conference on Health Informatics (BIOSTEC-Healthinf), ISBN: 978-989-8425-34-8, pp. 248-253, Rome, January 2011.
2) G.Orengo, G.Saggio, S.Bocchetti, F.Giannini, “Evaluating Strain Sensor Performance For Motion Analysis”, International Conference on Biomedical Electronics and Devices (BIOSTEC-Biodevices), ISBN: 978-989-8425-37-9, pp. 244-249, Rome, January 2011.
3) G.Saggio, S.Bocchetti, C.A.Pinto, G.Latessa, G.Orengo, “Non Uniform Geometry Bend Sensors Exploited for Biomedical Systems”, International Conference on Bio-inspired Systems and Signal Processing, (BIOSTEC-Biosignals), ISBN: 978-989-8425-35-5, pp. 389-392, Rome, January 2011.
Organic semiconductor devices and nanostructures
A. Di Carlo, A. Reale, F. Brunetti
Organic and nanostructured devices have been investigated, realized and simulated. Organic solar cells have been realized by using both a multilayer technology on ITO substrate. Both Graetzel and all-organic type cells
have been fabricated and characterized. Several techniques have been used for
encapsulation of the devices. All-plastic thin film transistors (OTFT) have been obtained via peeling techniques using contact electro-polymerization. Pentacene has been used as organic semiconductors. Carbon Nanotubes have been used to realize nanotriodes based on field emission. Several simulators have been developed to describe and optimize the behavior of organic devices
and nanostructures. A Green's functions based tool has been optimized to describe transport in carbon nanotubes and other molecular electronic devices. A new multiscale tool "TiberCAD" has been developed to describe transport in 1D/2D/3D organic devices.
Publications in 2011
1) F. Giordano, E. Petrolati, T. M. Brown, A. Reale, A. Di Carlo “Series-Connection Design for Dye Solar Cell Modules” IEEE TED, vol. 58, no8 (2011) - pages 2759-2764
2) G. Ulisse, F. Brunetti, A. Vomiero, M. M. Natile, G. Sberveglieri, and A. Di Carlo, “Hybrid thermal-field emission of ZnO nanowires”, Appl. Phys. Lett. vol.99, 243108 (2011)
3) D. D’Ercole, L. Dominici, T. M. Brown, F. Michelotti, A. Reale, and A. Di Carlo “Angular response of dye solar cells to solar and spectrally resolved light”, Appl. Phys. Lett. 99, 213301 (2011)
4) T. M. Brown, A. Reale, A. Di Carlo “Organic and Hybrid Solar Cells”, in Thin Film Solar Cells: Current Status and Future Trends, Nova Science Publisher, Inc. (2011) - pages 249-286 978-1-61668-326-9
5) T.M. Brown, G.M. Lazzerini, L. Parrot, V. Bodrozic, L. Burgi, F. Cacialli “Time dependence and freezing-in of the electrode oxygen plasma-induced work function enhancement in polymer semiconductor heterostructures” Organic Electronics (2011) - pages 1566
6) Paoloni, C.; Di Carlo, A.; Brunetti, F.; Mineo, M.; Ulisse, G.; Durand, A.; Krozer, V.; Kotiranta, M.; Fiorello, A.M.; Dispenza, M.; Secchi, A.; Zhurbenko, V.; Bouamrane, F.; Bouvet, T.; Megtert, S.; Tamburri, M.; Cojocaru, C.-S.; Gohier, A. “Design and Fabrication of a 1 THz Backward Wave Amplifier” Terahertz Science and Technology, vol. 4, no. 4 (2011) - pages 149-163
7) L. Dominici, D. Colonna, D. D’Ercole, G. Mincuzzi, R. Riccitelli, F. Michelotti, T. M. Brown, A. Reale, A. Di Carlo, “Dye Solar Cells: Basic and Photon Management Strategies”, Solar Cells - Dye-Sensitized Devices - Chap. 13 (2011) - pages 279–318 ed. L. Kosyachenko (InTech, Croatia, 2011)
8) Salamandra L.; Susanna G.; Penna S.; Brunetti F.; Reale A. “Time-resolved response of polymer bulk-heterojunction photo-detectors”, Photonics Technology Letters Vol: 23, Issue: 12 (2011) - pages 780-782
9) Bari D.; Wrachien N.; Tagliaferro R.; Penna S.; Brown T.M.; Reale A.; Di Carlo A.; Meneghesso G.; Cester A. “Thermal stress effects on Dye-Sensitized Solar Cells (DSSCs)”, Microelectronics Reliability Vol: 51, Issues: 9-11 (2011) - pages 1762-1766
10) Ulisse, G.; Brunetti, F.; Di Carlo, A. “Study of the Influence of Transverse Velocity on the Design of Cold Cathode-Based Electron Guns for Terahertz Devices”, IEEE Transactions on Electron Devices Volume: 58 , Issue: 9 (2011) - pages 3200 – 3204
11) A.Gagliardi, M. Auf der Maur, D. Gentilini and A. Di Carlo, “Simulation of Dye Solar Cells: through and beyond one dimension”, J. Comp. Elec. (2011)
12) Gagliardi, M. Auf der Maur, A. Di Carlo, “Theoretical Investigation of a Dye Solar Cell Wrapped Around an Optical Fiber”, IEEE Journal of Quantum Electronics, 47, 1214 (2011)
13) Auf der Maur, M. and Gagliardi, A. and Di Carlo, A., “Physics based simulation of dye solar cells”, Optical and Quantum Electronics (2011) - pages 1-7
14) Mincuzzi G., Vesce L., Liberatore M., Reale A., Di Carlo A, Brown T. M., “Laser-Sintered TiO2 Films for Dye Solar Cell Fabrication: an Electrical, Morphological and Electron Lifetime Investigation”, IEEE Transaction on Electron Devices vol. 58, issue 9 (September 2011) - pages 3179-3188
15) V. Zardetto, T.Brown, A. Reale, A. Di Carlo, “Substrates for flexible electronics: A practical investigation on the electrical, film flexibility, optical, temperature, and solvent resistance properties”, Journal of Polymer Science Part B: Polymer Physics, vol. 49, (2011) - pages 638-648
16) S. Prezioso, L. Ottaviano, F. Bisti, M. Donarelli, S. Santucci, L. Palladino, S. Penna, A. Reale, “Infrared photoluminescence of erbium-tris(8-hydroxyquinoline) in a distributed feedback cavity”, Journal of Luminescence 131 (2011) - pages 682–685
17) G. Susanna, L. Salamandra, A. Di Carlo, T. M. Brown, F. Brunetti, A. Reale “Airbrush Spray Coating of Polymer Bulk-Heterojunction Solar Cells”, Solar Energy Materials and Solar Cells, vol. 95, issue 7 (2011) - pages 1775-1778
Modeling and experimental study of nanostructured devices
A. D. Carlo, A. Reale
Several simulators have been used and/or developed to simulate the behavior of electronic and optoelectronic devices. Finite Element simulations have been
used to to study the electrical characteristics of GaN-based HEMTs. In particular we have optimized GaN based HEMTs with respect to frequency and power. Both electronic and optical properties of the nanonostructure has been calculated by means of k.p and tight-binding methods. A combined 3D drift-diffusion + strain simulator has been developed and implemented withing the TiberCAD simulator. The photoconductance method has been used to study the channel temperature in both GaAs and GaN based HEMTs.
Publications in 2011
1) Giuseppe Romano, Giulia Mantini, Aldo Di Carlo, Arnaldo D'Amico, Christian Falconi and Zhong Lin Wang, “Piezoelectric potential in vertically aligned nanowires for high output nanogenerators”, Nanotechnology vol. 22, 465401 (2011) - pages 6
2) G. Romano and A. Di Carlo, “Multiscale Electrothermal Modeling of Nanostructured Devices”, IEEE Transactions on Nanotechnology, vol. 10, issue. 6 (2011) - pages 1285 - 1292
3) Auf der Maur, M. and Penazzi, G. and Romano, G. and Sacconi, F. and Pecchia, A. and Di Carlo, A., “The Multiscale Paradigm in Electronic Device Simulation”, IEEE Transactions on Electron Devices vol. 58, n. 5 (May 2011) - pages 1425-1432
Micro-nano-systems for energy harvesting and medical applications
C. Falconi, A. D’Amico
L’obiettivo della nostra ricerca è l’analisi, il progetto, la realizzazione e la caratterizzazione di microsistemi e nanosistemi per energy harvesting e applicazioni mediche.
I risultati ottenuti includono:
- analisi del potenziale piezoelettrico in nanostrutture semiconduttiva quasi-1-dimensionali compresse verticalmente [1];
- definizione di nanostrutture piezoelettriche semiconduttive anti-simmetriche e non anti-simmetriche e di semplici strategie per rompere l’anti-simmetria e confronto delle prestazioni [2];
- progetto di micro-reattori (micro-hot-plates) ad elevata uniformità termica [3,4]
- monitoring on-line durante la sintesi di nano-strutture con metodi MEMS-compatibili [5-7]
- realizzazione e caratterizzazione di un sensore di umidità nano-strutturato [8]
- sintesi e applicazione di nanowires di ZnO [9,10]
Publications in 2011
1) G. Romano, G. Mantini, A. Di Carlo, A. D’Amico, C. Falconi, Z. L. Wang, “Piezoelectric potential in vertically aligned nanowires for high output nanogenerators”, Nanotechnology. 2011 Nov 18;22(46):465401.
2) R. Araneo, G. Lovat, P. Burghignoli, C. Falconi, “Piezo-semiconductive quasi-1D nanodevices with and without anti-symmetry”, Advanced Materials, DOI: 10.1002/adma.201104588
3) Lee Siang Chuah, Zainuriah Hassan, Y. Sivalingam, C. Di. Natale, C. Falconi, “Ohmic contacts properties of Ag/Ir metallization scheme on undoped ZnO nanorod”, ICYRAM12-A-0022
Sistemi sensoriali ed applicazioni in campo medico e spaziale
A. D’Amico, C. di Natale, M. Santonico, E. Martinelli.
Nell’anno 2011-20012 sono state svolte ricerche nei seguenti settori: medicale, spaziale e nano tecnologico. Nel campo medicale impiegando sistemi olfattivi artificiali sono state svolte attività in diversi contesti: rilevazione del cancro ai polmoni ed alla prostata tramite analisi delle urine. Inoltre sono state svolte ricerche in ambito europeo(progetto IMI-UBIOPRED)per lo studio dell’asma e delle patologie relative.
Nelle missioni spaziali ed in particolare in quelle di lunga durata l’utilizzo di sensori e sistemi sensoriali è di fondamentale importanza per il monitoraggio della qualità dell’aria e dello stato di salute degli astronauti. In questo contesto il gruppo Sensori dell’università di Tor Vergata è impegnato dal 2002 nella messa a punto di sistemi sensoriali per questi scopi come dimostrato dai progetti finanziati dall’Agenzia Spaziale Europea (ESA) ed italiana (ASI)che hanno portato alla realizzazione di due esperimenti nella stazione spaziale internazionale (ISS) durante le missioni ENEIDE (2005) e DAMA (2011).
Publications in 2011
1) Nardis, S., Pomarico, G., Tortora, L., Capuano, R., D'Amico, A., Di Natale, C., Paolesse, R.: Sensing mechanisms of supramolecular porphyrin aggregates: A teamwork task for the detection of gaseous analytes (2011) Journal of Materials Chemistry, 21 (46), pp. 18638-18644
2) Lvova, L., Verrelli, G., Stefanelli, M., Nardis, S., Di Natale, C., D'Amico, A., Makarychev-Mikhailov, S., Paolesse, R.: Platinum porphyrins as ionophores in polymeric membrane electrodes (2011) Analyst, 136 (23), pp. 4966-4976
3) Vergara, A., Martinelli, E., Huerta, R., D'Amico, A., Di Natale, C.: Orthogonal decomposition of chemo-sensory cues (2011) Sensors and Actuators, B: Chemical, 159 (1), pp. 126-134
4) Martinelli, E., Polese, D., Dini, F., Paolesse, R., Filippini, D., Lundström, I., di Natale, C.: An investigation on the role of spike latency in an artificial olfactory system (2011) Frontiers in Neuroengineering, (NOVEMBER)
5) Martinelli, E., Santonico, M., Pennazza, G., Paolesse, R., D'Amico, A., Di Natale, C.: Short time gas delivery pattern improves long-term sensor reproducibility (2011) Sensors and Actuators, B: Chemical, 156 (2), pp. 753-759
6) Dini, F., Martinelli, E., Paolesse, R., Filippini, D., D'Amico, A., Lundström, I., Di Natale, C.: Polymer matrices effects on the sensitivity and the selectivity of optical chemical sensors (2011) Sensors and Actuators, B: Chemical, 154 (2), pp. 220-225
7) Pennazza, G., Santonico, M., Martinelli, E., Paolesse, R., Tamburrelli, V., Cristina, S., D'Amico, A., Di Natale, C., Bartolazzi, A.: Monitoring of melanoma released volatile compounds by a gas sensors array: From in vitro to in vivo experiments (2011) Sensors and Actuators, B: Chemical, 154 (2), pp. 288-294
8) Eifler, J., Martinelli, E., Santonico, M., Capuano, R., Schild, D., Di Natale, C.: Differential detection of potentially hazardous fusarium species in wheat grains by an electronic nose (2011) PLoS ONE, 6 (6), art. no. e21026
9) Paolesse, R., Monti, D., Dini, F., Di Natale, C.: Fluorescence based sensor arrays (2011) Topics in Current Chemistry, 300, pp. 139-174
10) Sbardella, P., Monti, D., D'Epifanio, A., Stefanelli, M., Naitana, M.L., Venanzi, M., Di Natale, C., Paolesse, R.: Preparation and spectroscopic studies of silica nanoparticle-porphyrin hybrids held by noncovalent interactions (2011) Journal of Porphyrins and Phthalocyanines, 15 (5-6), pp. 382-390
11) Bussetti, G., Violante, A., Yivlialin, R., Cirilli, S., Bonanni, B., Chiaradia, P., Goletti, C., Tortora, L., Paolesse, R., Martinelli, E., D'amico, A., Di Natale, C., Giancane, G., Valli, L.: Site-sensitive gas sensing and analyte discrimination in langmuir-blodgett porphyrin films (2011) Journal of Physical Chemistry C, 115 (16), pp. 8189-8194
12) Penza, M., Rossi, R., Alvisi, M., Valermi, D., Serra, E., Paolesse, R., Martinelli, E., D'Amico, A., Di Natale, C.: Metalloporphyrin-modified carbon nanotube layers for gas microsensors (2011) Sensor Letters, 9 (2), pp. 913-919
13) Penza, M., Alvisi, M., Rossi, R., Serra, E., Paolesse, R., D'Amico, A., Di Natale, C.: Carbon nanotube films as a platform to transduce molecular recognition events in metalloporphyrins (2011) Nanotechnology, 22 (12), art. no. 125502
ALGORITHMS AND VLSI ARCHITECTURES FOR DIGITAL SIGNAL PROCESSING
G. C. Cardarilli
Collaborations: Thales Alenia Spazio, Selex S.I., Elettronica S.p.A., Centro Vito Volterra
In this research different techniques for the implementation of high speed and low power architectures for DSP are faced. The research investigates mainly the use of non-conventional number representations in order to obtain high speed and low power systems. The main topic is the use of the Residue Number System (RNS) and, in particular regards the input and output conversion blocks in fact, the Binary to RNS and the RNS to Binary converters, are bottlenecks in the implementation of high-performance RNS based DSP architectures.
In this research some new architectures for the output conversion have been developed. These architectures show some important implementation advantages. Moreover, the new techniques are interesting from the theoretical point of view. In fact, the new method generalizes the algorithms presented in the literature. In terms of the application of the RNS to subsystems, at present, the research has been focused on the simulation and development of complex coefficients FIR filters and polyphase filter banks based on the QRNS (Quadratic Residue Number System) arithmetic.
Another aspect of the research is the development of processing platform based on reconfigurable devices. The research analyzed the possibility to use this platform in autonomous radio for space application. The idea is to have a reconfigurable radio, able to adapt its communication standard to the divers rovers presents in a planet surface. A special high resolution DDS was also developed.
We also studied and developed a simulator for the study of radar based on compressive sampling. Compressive sampling is a new method that reduces the radar analog interface complexity (in particular the stages for IF conversion and the ADC) for special class of signals (called “sparse signals). This technique is very promising for the production of future radars.
A last topic considered in this research area is the design of hardware and mixed (hardware and software) architectures for crypto systems. In this frame we developed a set of architectures for communication and video flows.
Publications in 2011
1) Cardarilli, G.C.; Re, M.; Shuli, I.; Simone, L.; , "Partial reconfiguration in the implementation of autonomous radio receivers for space," Reconfigurable Communication-centric Systems-on-Chip (ReCoSoC), 2011 6th International Workshop on , vol., no., pp.1-6, 20-22 June 2011
2) Cardarilli, G.C.; Di Nunzio, L.; Fazzolari, R.; Pontarelli, S.; Re, M.; Salsano, A.; , "Implementation of the AES algorithm using a Reconfigurable Functional Unit," Signals, Circuits and Systems (ISSCS), 2011 10th International Symposium on , vol., no., pp.1-4, June 30 2011-July 1 2011
3) Cardarilli, G.C.; D'Alessio, M.; Di Nunzio, L.; Fazzolari, R.; Murgia, D.; Re, M.; , "FPGA implementation of a low-area/high-SFDR DDFS architecture," Signals, Circuits and Systems (ISSCS), 2011 10th International Symposium on , vol., no., pp.1-4, June 30 2011-July 1 2011
Design of Low-Power Systems for DSP
G. C. Cardarilli, M. Re
Collaborations: DTU Copenhagen
Reduction of the power consumption is today one of most critical tasks for a DSP system designer. We faced this issue considering the effects on power consumption of the arithmetic operators. We considered different methods to reach these objectives
The use of alternative number systems in the implementation of application specific processors has gained a remarkable importance in recent years because of the lower power consumption over their traditional (e.g. two's complement) counterparts. The renewed success of the Residue Number System (RNS) is mainly related to the low power requirements, but also to the availability of hardware platforms, such as FPGAs, particularly suitable for the implementation of RNS arithmetic blocks. Techniques to implement RNS operations are often based on look-up tables, which are the basic blocks to instantiate combinational logic in FPGAs. As the research shown, similar advantages are also obtained for ASIC technology.
In some DSP systems, output errors can be well tolerated in some mode of working. For this reason we can propose arithmetic operator with imprecise computation but very simplified structure. These operators are also characterized by a very reduce power consumption.
Publications in 2011
1) Albicocco, P.; Cardarilli, G.C.; Nannarelli, A.; Petricca, M.; Re, M.; , "Degrading precision arithmetics for low-power FIR implementation," (invited paper), Circuits and Systems (MWSCAS), 2011 IEEE 54th International Midwest Symposium on , vol., no., pp.1-4, 7-10 Aug. 2011
Reconfigurable processors for DSP
G. C. Cardarilli, M. Re
Collaborations: Princeton University, Thales Alenia Space, DTU Copenhagen, Elettronica S.p.A.
The idea of this research started with the observation that also in high performance systems, simple operations that are frequently repeated can produce performance degradation. This is related to the methods used for the optimization of the microprocessors and DSPs. Their architectures are focused to an efficient implementation of the most expensive operation as, for example, additions and multiplication, while the less common or less expensive operations are not implemented in hardware. As a consequence we have that simple operations not included in the original architectures produce a significant degradation of the performance. As an example we can cite operations that use a reduced number of bits (with respect to the native processor wordlength) or operations that don’t use each bit in the same way (considering two operands, some bits are xored, other bit are anded). The implementation of this operation is very inefficient for the scarce flexibility of the hardware operators. Our goal is to improve the performance (as speed and power consumption) of the processor accelerating these “simple” operations.
A possible solution for achieving the goals is the introduction of a reconfigurable hardware that is able to adapt itself to the specific operations required by the algorithms. This hardware is indicated as Reconfigurable Unit (or RU). In this way in the program we can mix conventional operations (those belonging to conventional Instruction Set , IS, of the processor) with special operations (i.e. operations implemented in the RU after the proper reconfiguration). In our work we consider the following constraints for the RU.
1) It must implement very simple operations
2) Each operation must be performed in a single or few clock cycles.
3) Its hardware complexity must be very low (if compared to the processor complexity). One of the most important task in the design of an efficient architecture based on a processor + a reconfigurable unit, is the definition of a suitable interfacing mechanism between these two resources.
With the integration of Hardware Accelerators in a standard microprocessor it’s possible to obtain a reduction of the microprocessor energy consumption with a significant performance improvement.
Publications in 2011
1) Cardarilli, G.C.; Di Nunzio, L.; Fazzolari, R.; Pontarelli, S.; Re, M.; Salsano, A.; , "Implementation of the AES algorithm using a Reconfigurable Functional Unit," Signals, Circuits and Systems (ISSCS), 2011 10th International Symposium on , vol., no., pp.1-4, June 30 2011-July 1 2011
2) Gian Carlo Cardarilli, Luca Di Nunzio, Rocco Fazzolari, Marco Re, “fine-Grain Reconfigurable functional Unit for Embedded Processors”, (invited paper), 2011 Conference Record of the Forty Fifth Asilomar Conference on Signals, Systems and Computers (ASILOMAR), 6-9 Nov. 2011
DSP PROCESSORS FOR HUMAN-MACHINE INTERFACES
G. C. Cardarilli, M. Re
Collaborations: Dip. Neurofisiopatologia, SkyTechnology, Santa Lucia
In this research is focused on the various signal processing techniques used to realize different kinds human-machine interfaces.
In the last years we focused our attention on brain-computer interface. A brain-computer interface allows a person to transfer thoughts and commands to a computer directly. Instead of using a keyboard, mouse, light pen or other input device, a user of such an interface simply thinks his or her commands and the computer responds to them.
Some of the latest work involves hooking a user up to electroencephalography sensors (better known as EEG sensors) that are connected to a computer on one end and the user's head on the other. The user wears a kind of cap with sensors on it designed to capture brain activity, and the interface measures the subject's brain responses and sends the information to a computer running a particular application such as a text input program.
We developed different methods for the processing EEG signals in order to extract the useful information. Moreover we developed a system for the acquisition of the brain signals stimulated by blinking lights and for controlling the different options in a menu.
Publications in 2011
1) L.R. Quitadamo, M. Abbafati, G.C. Cardarilli, D. Mattia, F. Cincotti, F. Babiloni, M.G. Marciani, L. Bianchi “Evaluation of the performances of different P300 based brain–computer interfaces by means of the efficiency metric”, Journal of Neuroscience Methods, Volume 203, Issue 2, 30 January 2012, Pages 361-368 ISSN: 0165-0270