44-GHz tracking low-noise amplifiers for Milstar MDR nulling antenna

Abstract

A cluster of thirteen low-noise amplifier (LNA) modules, that drive nulling as well as quiescent G/T requirements of the Milstar MDR nulling antenna system, have been designed, fabricated, and tested for the first time. The key parameters such as noise figure, gain, and amplitude and phase tracking of thirteen hermetically-sealed LNA modules were measured over temperatures (from -7/spl deg/C to +52/spl deg/C) and biases (Vd=2.5 V/spl plusmn/5%, Vg=-1.5 V/spl plusmn/2%). Under the worse case condition (i.e., temperature=+52/spl deg/C, Vd=2.375 V, Vg=-1.53 V), the thirteen LNA modules have achieved noise figure of less than 4.3 dB, gain of better than 19.2 dB, peak-to-peak amplitude tracking of 0.4 dB, and peak-to-peak phase tracking of 4 degrees across 43.5-45.5 GHz band, meeting all the requirements. The tracking performance from the thirteen LNA modules is the best ever reported at 44 GHz.