Source-pull characterization of differential active antennas for radio-astronomy applications

Differential amplifiers have been proposed as an efficient solution for the planar aperture arrays in the low frequency band of the SKA project. The characterization of this type of devices is not the typical one, and they need of some specific techniques. On the other hand, the use of antennas matched to a non-50 Omega impedance requires of source-pull techniques for an accurate measurement. In this paper, two different techniques for differential source-pull measurements in terms of gain and noise figure are proposed. Both techniques are described in detail, analyzing the advantages and disadvantages of each one.