Pulsed-field antenna analysis, design and optimization using direct electromagnetic time-domain concepts
Adrianus T. de Hoop and Ioan E. Lager
Traditionally, the analysis, design and optimization of antenna systems for radar and (mobile)
communication takes place via a frequency-domain characterization of the electromagnetic field and (equivalent) electrical
circuit quantities involved.
However, as soon as the information content of the signals involved is coded as sequences of pulses, the field behaviour
in time becomes the prime issue and a direct time-domain characterization does present itself as a natural tool for the
description of the phenomena. Such a description focuses on the physical changes in magnitude and/ or shape of each
individual pulse on its passage from its generation to its detection, rather than on the pulse repetition rate of the
sequence (as a frequency-domain analysis would fundamentally do). Notwithstanding this argument in favour of handling
pulsed-field antenna analysis, design and optimization directly in the time-domain, the available literature on the subject
is scarce, while it deals with wire antennas (electric dipole antennas) and loop antennas (magnetic dipole antennas) only
[1,2], with their Kirchhoff circuit description of the field behaviour near the accessible feeding ports. Even for these
simple structures already a time-domain analysis shows that during its propagation from transmitter to receiver an emitted
pulse undergoes a change in shape, where the replica of the exciting electric current, as well as its time-integrated and
time-differentiated counterparts, each weighted with directional and distant dependent amplitude factors, play a combined role The arguments above are at the origin of a cooperation initiated between the Laboratory of Electromagnetic Research and
IRCTR. In view of the incipient stage of this activity, the talk will be confined to an outline of the goals/ ambitions of
this line of research.
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