Current and future developments of lightweight waveguide SAR antenna arrays

The synthetic aperture radar antenna panels assemblies (SAPA) forms the radiating part of the Radarsat´s SAR antenna which when deployed, is a 15m×1.5 m planar array. The SAPA is constructed entirely in aluminium alloy. Adhesive bonding is used throughout. The choice of lightweight aluminium slotted waveguide was made early in the program despite other options being pursued by others. Aluminium waveguide technology has proven very successful. Very few development problems have been experienced and both RF and mechanical performances are close to expectations. The waveguide provides an exceptionally low-loss path and accurately repeatable array elements. Component design, for power dividers and other units in the SAPA microwave circuit, has been relatively simple while construction methods have enjoyed the use of standard adhesives and fixing systems. An added benefit is that waveguide is a useful structural element