A Low-Noise, High-Linearity Amplifier for Wireless Base-Stations

In this paper, a 0.1–1.5 GHz high-linearity low noise amplifier (LNA) is designed based on a 0.5 $\mu$m GaAs pHEMT process, which employs one stage 2-stacked-FETs to obtain a broadband gain performance and wideband impedance matching. Biasing with a 5 V drain voltage and 101 mA quiescent current, this LNA shows measurement results of about 0.1-watt power performance in the frequency range of 0.1–1.5 GHz with a output third-order intercept point (OIP3) of above 39 dBm. The measured S-parameters show a gain (S
21
) of 13 to 25 dB, a maximum input return loss (S
11
) of −19 dB, a maximum output return loss (S
22
) of −12 dB. The chip occupies a small chip size of $0.7 \times 0.65$ mm
²
. Using a loadpull system, this LNA can maintain high OIP3 of above 35 dBm against a wide load impedance range.