Realization of Wideband Hologram Compact Antenna Test Range by Linearly Adjusting the Feed Location

Hologram-based compact antenna test range (HCATR) is very attractive for antenna measurement at mm/sub-mm wave frequencies. However, as the hologram is a frequency sensitive element, the operation of a HCATR is usually limited to a narrow band. This paper describes a wideband HCATR: It can be realized by linearly adjusting the feed location. The position needs to be adjusted for approximately compensating the wave front curve of the feed, which is proportional to the operating frequency. The theory can be conformed under the paraxial condition. For the acceptable quiet zone field quality over a wide band, the aperture needs to have a large focal ratio. The idea is verified and the wideband performance of the quiet zone is studied with the simulated and measured results at W band (95 GHz) and D band (170 GHz).