Evaluation of microwave antenna test range performance

Evaluation of microwave antennas may involve recording the radiation pattern on a conventional outdoor far field range and this has highlighted a new measurement problem. It is well known that any measurement facility is limited in dynamic range by the degree of environmental scattering due to natural or man made objects in the vicinity. The authors describe a means of evaluating the measurement range performance from diagnostics of the wavefront incident upon a surface enclosing the antenna. Environmental effects are highlighted as regions of focussed high field intensities, thus providing information about the location and relative significance of unwanted scattering objects which have been illuminated by the transmitting probe. These scatterers can then either be physically removed or suppressed, or be propagated to the far field and used as a site signature in a deconvolution process with the measured antenna pattern