Problems of wideband waveguide-slot antennas design

Physical limits of the operational frequency band of slotted waveguide antennas are studied. It is shown that by using both conventional longitudinal slots and sub-arraying techniques it is possible to reach the relative bandwidth of about 15%. These results are illustrated by the development of genuine slotted waveguide antenna that operates in the X-band and forms the beam of 4degtimes6deg with the gain of about 30 dB.