Wideband Low-Noise-Amplifier (LNA) with Lg = 50 nm InGaAs pHEMT and wideband RF chokes

This paper presents a 2-stage Low-Noise-Amplifier (LNA) MMIC which provides ultra-low-noise, broad bandwidth, and high associated gain while consuming a fairly low DC power dissipation of 20 mW. The amplifier has been fabricated using L_g = 50 nm enhancement-mode (E-mode) In_0.7Ga_0.3As pHEMTs on a 4-mil InP substrate. By using broad bandwidth RF chokes, the LNA exhibits an average noise figure (NF) of 1.1 dB from 4 to 24 GHz with a minimum associated gain (G_a) of 17 dB. To the knowledge of the authors, this is the first demonstration of an LNA that covers from C-band to K-band with NF <; 1.1 dB. This is allowed for by combining the extremely low NF characteristics of an advanced InGaAs pHEMT with broadband RF chokes.