Higher order versus first order Probe Correction techniques applied to experimental spherical NF antenna measurements

Probe Correction (PC) in Spherical Near Field (SNF) measurements is typically performed involving the so called first order PC algorithm [1]-[3] which assumes probes with limited |μ|=1 spherical wave spectrum. Lot of effort is typically put in the developments of probes with such requirement [4]-[5] but their design is in many case very challenging especially for wide-band applications. In order to have less restrictions in the selection of the probe, different full probe correction techniques have been recently proposed [6]-[9]. In this paper the accuracy and limitation of the first and higher order PC algorithms are investigated considering the SNF measurement of a wideband horn measured with a first order probe and with a standard gain antenna with higher modal content. The full PC algorithm here considered is based on the modification of the spherical basis functions that are properly elaborated taking into account the effect of the probe.