Speaker:
Dr. Paul Tasker
Cardiff University
Title:
RF I-V Waveform Measurement and Engineering -
the unifying link between transistor technology, circuit design and system performance
Date:
Friday, July 23, 2010
Time:
11:00 am - 12:00 noon
Location:
EIT 3142
Abstract:
Microwave power amplifier performance, output power, conversion
efficiency and linearity, etc., is significantly influenced by the
terminal voltage and current time varying waveforms that develop at the
transistor terminals; terminal waveforms are the unifying theoretical link
between transistor technology, circuit design and system performance.
Thus waveform engineering should be a major objective driving the power
amplifiers design flow. However, in practice power amplifier design,
while waveform engineering may be a guiding principle, the lack of
appropriate RF waveform measurements tools has hindered its direct
application at microwave frequencies. However, the past 10 years has
seen the development of a number of RF characterization systems capable
of measuring RF voltage and current waveforms. Coupling such systems
with impedance control hardware also enables experimental control
(Engineering) of these terminal RF waveforms during measurements; thus
providing a practical RF Waveform Measurement & Engineering solution.
This lecture will discuss these emerging systems and show they are
now finally enabling practical waveform engineering to be directly
undertaken within the power amplifier design flow. Design support
can involve either direct utilization of the measurement system in the
design investigation/evaluation loop, or indirect use by providing CAD
accessible datasets.
Biography:
Paul J Tasker has been working in the field of microwave and millimetre
wave device & circuit characterization for over 25 years. He obtained a
BSc in Physics and Electronics in 1979 and a PhD in Electronic Engineering
in 1983, both from the Leeds University. He has worked (1984-1990) as
research associate at Cornell University with Lester Eastman involved in
the design and development of high frequency transistors. From 1990-1995
he was a senior researcher and manager, at the Fraunhofer Institute
for Applied Solid State Physics (IAF) in Freiburg Germany, responsible
for the development of millimetre wave MMICs. He joined the School of
Engineering at Cardiff University as Professor in the summer of 1995.
While at Cardiff he has establishing, and now Directs, the Cardiff
University and Agilent Technology Centre for High Frequency Engineering.
The Centre's research objective is to pioneer the development and
application of RF I-V Waveform and Engineering Systems, with a particular
focus to addressing the PA design problem. This centre is working with
a number of national and international companies; i.e. Nokia, Freescale,
Inphi, QinetiQ, Filtronic, IQE, SELEX, Mimex Broadband etc. in both the
commercial communication and military sensor fields. He has contributed
to over 200 journal and conference publications and given a number of
invited conference workshop presentations. He is a Fellow of the IET
and a Senior Member of the IEEE.
Invited by:
Prof.
S. Boumaiza
