An analytical treatment of the compact range.

Using reciprocity we find that a compact range can in principle measure the same return from a target as would be measured by an antenna irrespective of whether either the antenna or the target lies in the other's near or far field. Although the results depend upon the capability of the compact range to emulate the antenna's near or far fields, an expression is given for the correction necessary when this is not completely achieved. Range size is also considered.