Sub-1.3 dB noise figure direct-coupled MMIC LNAs using a high current-gain 1-μm GaAs HBT technology

Abstract

Here we report on direct-coupled HBT MMIC LNAs which achieve sub-1.3 dB noise figures up to 2 GHz. This is believed to be the lowest noise figure (NF) reported for a 50/spl Omega/ MMIC-matched LNA in this frequency range. The LNAs are based on a new 1-/spl mu/m GaAs HBT technology which provides high DC current gains of >400 and f/sub T/'s in excess of 40 GHz and enables low broadband amplifier noise figure performance. A DC-3.2 GHz HBT LNA (DCLNA2) design achieves a gain of 24.6 dB and sub-1.3 dB NF up to 2 GHz while consuming only 7.8 mA of current. The minimum LNA noise figure is 1.22 dB at 1.5 GHz. A DC-6 GHz design (DCLNA1) achieves 26.1 dB gain and a NF less than 2 dB up to 4 GHz while consuming 16.4 mA. The NF at 6 GHz is 2.52 dB with a corresponding IP3 of 11 dBm. These HBT MMICs provide a low cost LNA solution for receiver applications encompassing the industrial-scientific-medical (ISM) wireless bands.