Development of a low-noise active balun for a dual-polarized planar connected array antenna for ASKAP

We describe the development of a low-noise active balun for a dual-polarized planar connected array antenna operating in the 0.7-1.8GHz frequency range. The device consists of two single-ended low-noise amplifiers (LNAs) operating at ambient temperature with a passive output-side balun. Issues of device characterization, matching and stability are discussed and techniques for measuring the signal and noise parameters are described. The viability of the approach is confirmed by preliminary measurements of noise temperatures less than 60K on a 5 × 4 array.