This thesis deals with the investigation and development of low pröle, low loss
antennas with emphasis on reduced cost implementations for di erent commu-
nication and radar applications in the microwave and millimeter-wave region.
All antennas investigated in this work are implemented in the K-band (18 GHz
26.5 GHz) as for this frequency range measurement facilities and power ampli-
ers were readily available, but actually they lend themselves for applications in
the mm-wave range where the low loss characteristic of the NRD-guide is even
more pronounced.