Abstract:
Slotted waveguide antennas are very attractive for radar and communication
applications. The design of these antennas require design curves, which relate
electrical parameters of waveguide slots such as admittances and resonant frequencies
to their physical parameters such as slot lengths and slot offsets. These design curves
were typically generated by making repeated measurements on fabricated antennas. In
this thesis FEM based EM analysis software has been used to generate the required
design curves. In particular, design curves have been obtained for broad wall
longitudinal radiating slot and broad wall centered-inclined coupling slot in a standard
waveguide WR51 and a custom designed waveguide. For radiating slot, design curves
like resonant length against slot offset, resonant conductance against slot offset and
off-resonance admittance against slot length have been found. For coupling slot;
resonant slot lengths and scattering parameters have been found over a range of slot
inclination. Using these design curves, various Ku band low side lobe planar array
antennas have been designed with Elliot's design procedure. The design procedure
requires computationally extensive iterations. A MA TLAB code has been developed
for these computations. The performance of the designed antennas has first been
checked in an FEM analysis software. Two of the designed antennas have then been
fabricated and tested and the measured results show that the performance of antennas
is in good agreement with that predicted by simulations.
