Lens-Type Compact Antenna Test Range at MM-Waves

A lens-type compact antenna test range (CATR) has been studied both theoretically and experimentally. For a lens with low dielectric constant ϵ_r, the surface accuracy requirement is much less stringent than for a reflector. An experimental CATR with a shaped polyethylene (ϵ_r, = 2.32) lens was made at 110 GHz. In order to make the amplitude ripple in the quiet zone small, the use of saw tooth serrations around the lens was studied. Theoretically the quiet zone field is exellent (peak to peak ripple 0.27 dB). Preliminary measured values are promising (peak to peak ripple 2.0 dB).