A Low Noise Integrated 0.3-16 GHz Differential Amplifier for Balanced Ultra Wideband Antennas

A 300 MHz-16 GHz, Low noise, wideband differential amplifier (active balun) for balanced ultra wideband antennas realized in a commercial low-cost 150 nm GaAs-mHEMT process, is described. The amplifier has demonstrated a differential gain of 25 dB and a common mode rejection of more than 30 dB. A 3-dB bandwidth of 16 GHz is achieved. The measured noise figure is below 1 dB in most of the band. A method for measuring noise figure of differential amplifiers at microwave frequencies is proposed and demonstrated experimentally.