Interference-pattern intermediate-distance antenna measurement technique

A new antenna-pattern measurement technique for antennas with large-field distances is described. The method is applicable to conventional ranges with 2-axis positioners and receivers that work in amplitude only. Basically, the technique is to make pattern measurements on a conventional finite-length range in the normal way but with a third antenna or an auxiliary circuit that causes interference. Interference patterns and finite-distance amplitude patterns are recorded and the finite-distance phase distribution extracted by data processing. This finite-distance data is then the input to a near-field/far-field transformation computer program that gives the far-field patterns.