Time Gating of Antenna Measurments II

Authors: Doren W. Hess, Victor Farr

Publication: AMTA 1988

Copyright Owner: NSI-MI Technologies

Currently many new compact range facilities are being constructed for making antenna pattern measurements indoors. Limited suppression of stray signals -- due to range layout, confined surroundings and residual absorbing material reflectivity -- represents a limitation on the accuracy of the measurements made in these facilities. Time-gating of the compact range signal appears to be very attractive technique to reduce unwanted reflections.

The authors have carried out an experimental investigation of time gating in a compact range. it is demonstrated that time-gating can improve the uniformity of the aperture field by removing the feed backlobe radiation; and, it is demonstrated that time-gating can remove the effects on a pattern of certain room reflections and of feed backlobes.

When compared to conventional methods of reducing reflections based on placement of absorber, time gating appears equivalent. It does not appear however that time gating improves the conventional methods, except for measuring wide beamwidth antennas.