A dual beam slotted waveguide array antenna for SAR applications

The authors describe the design process and test results of a dual beam array antenna model. The objective of this ESA funded program is to study the realization of dual beams in a waveguide slotted array of the ERS-1 SAR type (10 m×1 m). The experimental model is 1 m×1 m and comprises 24 slotted waveguides and a Blass matrix feed network. The synthesis and design of the array and Blass matrix is described. Calculated and measured results of the experimental model are presented. The key component in the Blass matrix is a crossguide coupler. The authors present a novel design of a crossguide coupler which makes it possible to realize very tight coupling