Compact dual band feed for Mars global surveyor

The goal launching of a planetary probe in late 1996 required the rapid development of a feed antenna for a spacecraft mounted 1.5 meter Cassegrain reflector for communications over the Deep Space Network. The lower frequency band (the primary mission) covers the range 7.17 GHz to 8.425 GHz while the upper frequency band is centered at 32 GHz (the secondary experiment). The primary reflector f/D is 0.33 while the subreflector raises the effective f/D to 1.46. The feed antenna design must fit the existing hardware. A reasonably good design was obtained through application of design rules and the building of a test antenna with adjustable parameters.