Occurrence of Grating Lobes and Their Suppression in Broad Wall Slotted Array of Shunt Slots

Abstract

Usually, the linear slotted waveguide arrays employing longitudinally displaced slots on broad wall exhibit higher sidelobes, in particular Gruenberg lobes at ±45° as compared to theoretically designed value. The occurrence of such higher lobes has been investigated theoretically as well as experimentally. The theory has been extended to the suppression of these lobes. The improved design technique based on previously unemployed theory has been developed and used in the design of linear array. The experimental results demonstrate the effectiveness of the technique. The present technique is a significant improvement over the existing ones.

Indexing terms:

• Slotted waveguide arrays
• Grating lobes
• Slots offsets
• Group factor
• Second order beams
• Element factor