The thesis treats the electromagnetic CAD modeling of
some important components
useful for designing multilayered radio front-ends and
active antennas. The models
developed are flexible to use and computationally efficient for
optimization together with
active circuits.
The steps leading to the development of accurate CAD models of
antennas suitable for designing active antennas is presented.
We considered edge fed
and aperture coupled microstrip antennas. The
implementation of the program is based
on accurate cavity and transmission line models.
The CAD models of the antenna are
also extended to incorporate micro-machined
antennas. Simulations are compared
with real experiments.
An efficient method for analysis of slots in the ground
plane of transmission lines based
on a spectral domain method is also introduced. The
application of non-resonant slots
in the matching of microwave amplifiers showed
improved noise and gain
characteristics when compared to traditional
transmission line matching techniques.
Based on transverse resonance techniques CAD
models of sandwich-slotlines were
developed. Simulations indicate good performance
for silicon based
sandwich-slotlines. Nonradiative dielectric (NRD)
connectors is another interesting
candidate for designing multilayered integrated circuits.
The coupling between NRD
connectors and microstrip lines is studied by
incorporating a transmission line model.
Moreover a dual polarised NRD plug based
antenna structure is presented.
Flexibility of use is one important
design issue considered in the
development of the models. Since object oriented
programming is used in
the development of the CAD models, the models
of different components can be coupled
by means of powerful optimization tools and active circuit
simulators.
