Scuola di Dottorato in Scienze ed Ingegneria dell'Informazione
DOTTORATO DI RICERCA IN INGEGNERIA ELETTRONICA INFORMATICA E DELLE
TELECOMUNICAZIONI
Short course on:
“RF electronics for wireless communication and remote sensing systems”
13th, 14th and 20th July 2010, Facoltà di Ingegneria, Viale Risorgimento 2, Bologna
Summary
The main technological issues and circuit design challenges arising in the
development and manufacturing of the RF front-end electronics for the next
generation (terrestrial or space-born) radio communication and remote sensing
systems will be synthetically outlined, with the aim of also pointing out both the
specific design tool requirements and a number of related research topics.
Actually, the ever-increasing computational power of DSP electronics allows for the
digital implementation of a relevant number of otherwise analogue signal processing
functions (e.g. not only relatively low-frequency mo/demodulation, but also fully
digital filtering and processing of high-frequency IF signals), with all the advantages
of the Software Defined Radio approach: flexibility, re-configurability, frequency
agility, reliable fault-tolerant design.
However, the main system performance parameter (e.g. S/N ratio, bit error rate,
power consumption, reliability) still strongly depend on the characteristics (e.g. nonlinear distortion, output power, noise, dynamic range, interference resistance, power
added efficiency) of the RF electronic circuits playing a fundamental role in the
receiver and transmitter front-ends of wireless systems: Power Amplifiers, LowNoise Amplifiers, Voltage Controlled Oscillators, mixers, Frequency Synthesizers,
fast A/D and D/A converters. This is particularly true for the next generation wireless
systems, where much stronger constraints on broad-band RF circuit performance
derive from the performance requirements of high-capacity, highly-flexible, compact,
multiple input/output wireless systems.
Thus, by considering specific case studies, special attention will be paid to noise,
non-linear distortion and interference resistance in broad-band LNAs and A/D
conversion channels, phase-noise in VCOs for frequency synthesizers, and the tradeoff issues between non-linear distortion, output power and power-added efficiency in
RF power amplifiers. Different application scenarios, with associated circuit
performance requirements and technological solutions in the areas of terrestrial
communication systems and satellite remote sensing/communication payloads, will
be described by experts from industrial R&D labs.
The short course is organized as a set of integrated seminars according to the
following programme:
Tuesday 13th July, Facoltà di Ingegneria, Aula 5.5.
9.30 a.m to 10.00 a.m. Fabio Filicori, Università di Bologna:
Goals and contents: foreword on main issues and research topics in RF
electronics for wireless communication and remote sensing systems
10.00 to 11.00 a.m.: Maurizio Pagani - Ericsson Design Centre
New hardware solutions in future microwave links for mobile network applications
New components are required for the next generation of microwave links in mobile backhaul
applications in order to increase capacity, energy efficiency, and manufacturability. Faster and more
energy efficient mobile communication is expected in microwave link systems operating at 4-38
GHz. Present data rates up to 170 Mbps in a single channel must be radically increased in future
systems to meet concurrent evolution in broadband mobile networks. The new components which
are based on advanced semiconductor technologies and microwave circuit designs, will allow
reducing costs, enhancing the performance and enabling new system solutions, more compact and
flexible than the existing ones.
This will be addressed by directing research towards novel reconfigurable circuit solutions, in
particular focusing on highly linear receivers and high efficiency linear transmitters, fabricated in
new semiconductor technologies combined with a new functional design approach.
Tuesday 13th July, Facoltà di Ingegneria, Aula 5.5.
11.00 a.m to 13.00 p.m. : Fernando Marchetti and Marziale Feudale -Thales Alenia
Space
Remote Sensing: from Earth Observation to Space Exploration
This presentation provides an overview of the satellite remote sensing equipment used in Earth
Observation and Planetary Exploration. After recalling the basics of operation and different
application scenarios of satellite payloads for remote sensing, the present and future architectures
of the RF front-ends of Earth-Observing and Planetary Exploration Radars (SARs in particular)
and Radiometers will be outlined, by pointing out the main requirements in the design of the basic
building blocks (Receivers, Up/Down Converters, Transmitters, Frequency Generators,..) of the
satellite RF equipment for radar payloads.
Present and future technological issues in the manufacturing of satellite RF payloads will be
outlined, by also considering the specific requirements (reliability, radiation resistance, power
consumption, weight, ..) associated with space-born electronic equipment.
Tuesday 13th July, Villa Griffone, Pontecchio Marconi
15.30 a.m. to 17.30 p.m.: Barbara Valotti, Maurizio Bigazzi-Fondazione G. Marconi
Guided visit to the Guglielmo Marconi Museum
This guided visit will provide a synthetic, historical yet stimulating (for both young and not-soyoung researchers) description of the first experiments, evolution and achievements in the very
early development of radio communication techniques, by directly examining the operating modes
of the functioning prototypes of Marconi’s wireless communication equipment
Wednesday 14th July, Facoltà di Ingegneria, Aula 5.5.
9.30 a.m. to 10.30 a.m.: Alberto Santarelli, Università di Bologna
Non linear distortion and dynamic range issues in the design of microwave
electronics for communication and remote sensing systems
-Non linear distortion, noise and dynamic-range issues in the basic circuits used as the building
blocks in RF electronics for wireless communication and remote sensing systems.
- Trade-off issues between nonlinear distortion, output power and power added efficiency in the
design/optimization of highly-linear microwave power amplifiers for high capacity radio links.
-Basics of new generation electron devices and modeling/design tools for low-distortion, highdynamic-range microwave circuit design.
Wednesday 14th July, Facoltà di Ingegneria, Aula 5.5.
10.30 a.m. to 12.30 a.m.: Alessandra Costanzo and Diego Masotti, Università di
Bologna
Integration of Nonlinear, Radiation, and Propagation Analysis Techniques for
circuit-level Design of entire RF links
The lecture will describe a CAD procedure for the circuit-level simulation of entire modern RF
links, such as SISO (Single Input Single Output), MIMO (Multiple Input Multiple Output), and
UWB (Ultra Wide Band) links. Due to the miniaturization of such systems, an integrated analysis/
design at the circuit level allows to accurately account for the nonlinear interaction among
subsystems. The lecture will first describe the main building blocks to be concurrently analyzed.
A SISO link example will be first described and the simulation from the transmitter to the receiver
intermediate-frequency ports is considered by means of nonlinear analysis coupled with the
electromagnetic characterization of the transmitter and receiver front ends. In the MIMO case, the
multiple transmitting and receiving antennas are described as one multiport radiating systems, by
EM analysis, thus accounting for mutual couplings in terms of the frequency-dependent near-field
and far-field performance. Furthermore the transmitters are treated as a unique nonlinear system
loaded by the multiport antenna, and analyzed again by nonlinear circuit techniques. The same is
done for the set of receivers. Both in SISO and MIMO cases, the connection between transmitters
and receivers is established by means of the following steps: i) the radiated far-field is evaluated by
EM analysis, and the field incident on the receiver side is computed by an available ray tracing
technique; ii) EM theory is then used to describe the receiving (single- or multi-port) antenna as a
linear active single- or multi-port network. BER computation and minimization is demonstrated for
the first time at the circuit level with affordable computational efforts.
Similar simulation approach will be applied to the analysis of pulse-UWB receiver front ends in the
presence of interfering communication signals. Interference effects on the nonlinear regime of
UWB receivers and accurate circuit-level prediction of receiver sensitivity and channel capacitance
will be discussed as the results of this analysis.
Wednesday 14th July, Facoltà di Ingegneria, Aula 5.5.
15.00 a.m. to 16.00 p.m.: Corrado Florian, Università di Bologna
Nonlinear noise in RF and microwave communication front-ends: theory,
modelling and practical examples
Electrical noise is a limiting factor for the performance of communication circuits, both under
small- and large-signal operation. This contribution will focus on the effects of nonlinear noise on
the performance of oscillators and low noise amplifiers. Special emphasis will be given to oscillator
circuits, covering some basic aspects of their design and describing the different topologies and
technologies adopted in their implementation. The main topics covered by the seminar are:
- Basics of noise in electronics components: broad-band noise and low-frequency noise in linear
and non linear operation.
- Oscillator design: small-signal and large-signal analysis; different oscillator topologies and
technologies: quartz-stabilized, DRO, VCO, differential and push-push architectures.
- Noise in oscillators: Phase Noise definition, generation mechanism and effects; PN minimization
techniques.
-Noise in amplifiers: Noise Figure in small-signal operation and nonlinear operating conditions;
non-linear noise generation, characterization and modelling for Low-Noise Amplifiers in the
presence of strong interfering signals.
16.00 a.m. to 17.00 p.m.: Pier Andrea Traverso, Università di Bologna
RF Analogue-to-Digital conversion channels
Receiver front-ends for a wide family of both terrestrial and satellite communication/sensing
systems take advantage of the ever-increasing performance of A/D converters and related circuits.
The recent improvements in terms of real-time sampling frequency, vertical resolution, linearity and
reliability allow for the design and implementation of broad-band A/D conversion channels directly
at RF, with a significant reduction of the frequency down-conversion analogue circuits between the
antenna system and the section at which the signals are converted to digital. In this talk the
following topics will be addressed:
-Basics of analogue-to-digital conversion techniques. Architectures for fast A/D Converters (ADCs)
oriented to the sampling and quantization of RF signals.
-Experimental characterization procedures and performance evaluation of A/D conversion channels.
-Non-linear dynamic modelling and algorithmic compensation of the non-idealities within RF A/D
conversion channels using a modified Volterra-based approach.
Wednesday 14th July, Facoltà di Ingegneria, Aula 5.5.
17.00 a.m. to 18.00 p.m.: Rudi Paolo Paganelli, Istituto di Elettronica e di
Ingegneria dell'Informazione e delle Telecomunicazioni-CNR
Microwave power amplifiers for satellite remote sensing and communication
Design issues of high-efficiency power amplifiers for microwave transmitters in satellite payloads
are dealt with by examining the most important figures of merit in relation to some typical transistor
operating classes (A, AB, B, etc..). After considering a nearly ideal active device in the assessment
of general criteria for load-line and operating condition optimization, also non-ideal effects in
power electron devices will be considered. Possibility of achieving higher levels of efficiency by
adopting a near-switch-mode transistor operation even at microwave frequencies will be also
examined. Power dissipation, maximum channel temperature for reliable operation and thermal
stability problems will also be discussed. Two practical examples of HPA design will be illustrated
for two different technologies (pHEMT, HBT) and classes of operation (AB, E).
Finally, examples of power amplifier architectures optimizing efficiency or linearity in applications
with advanced modulation schemes are briefly illustrated.
Tuesday 20th July, Facoltà di Ingegneria, Aula 5.1
10.00 a.m. to 12.00 a.m.: Eleonora Franchi, Antonio Gnudi, Marco Guermandi,
Università di Bologna
Frequency synthesizers for RF transceivers
-Short introduction to frequency synthesis for integrated RF transceivers.
-Phase locked-loops (PLL): architecture, waveforms, building blocks (phase-frequency detectors,
charge pump, loop-filter, VCO, frequency dividers).
-Modelling of PLL in the frequency and time domain; Noise in PLLs.
-Design examples:
1) Synthesizer for UWB receivers
2) Synthesizer and VCOs for fully-integrated reconfigurable multi-standard transceivers: high
tuning-range VCO, fractional-N synthesizers with techniques for spurious compensation and
increased linearity.