Low noise and high linearity LNA based on InGaP/GaAs HBT for 5.3 GHz WLAN

This paper presents a low noise and high linearity LNA based on InGaP/GaAs HBT for 5.3 GHz WLAN. Previous LNAs based on FET series such as HEMT show excellent noise characteristics, but poor linearity. The InGaP/GaAs HBT LNA shows excellent linearity and noise characteristics because of its high base doping concentration. The proposed LNA is fully integrated in area of 0.9 /spl times/ 0.9 mm/sup 2/ single chip with high Q spiral inductors and MIM capacitors and biased at current point for optimum noise figure and gain characteristics, furthermore, excellent linearity is achieved. Measured result of the proposed LNA shows 13 dB gain, 2.1 dB noise figure, and excellent linearity in terms of IIP3 of 5.5 dBm. The figure of merit (FOM) defined as a function of the linearity and noise figure is 20.1 dB, which is the best result among previous LNAs.