Pressure-formed parabolic reflectors for millimeter wavelengths

An empirical investigation of metallic diaphragms deformed by uniform normal pressure to produce accurate parabolic reflectors is discussed. 30-cm diameter (
f/D =0.4
) reflectors produced by this technique were measured mechanically and found to have maximum deviations of only 0.5 mm or
\lambda/20
at 30 GHz from a true paraboloid within a circle of 14-cm radius. Electrical measurements at 30 GHz are discussed.