Design of GaAs RF front-end LNA

A wideband low noise amplifier with high-linearity, high-gain and ultra-low noise is designed and fabricated in a 0.25 μm GaAs pHEMT process. A matching network is used between common-gate and common-source transistors in this circuit to obtain larger power gain in higher bands. The measurement results show that the quiescent current of the LNA was 75 mA in 5 V power supply. After external matching in three bands of 0.7~1.0 GHz, 1.6~2.2 GHz and 2.3~2.7 GHz, the LNA respectively provide a high and flat gain of 27.2~25.8 dB, 22~20 dB and 19.2~18.7 dB, a low noise figure of 0.45~0.75 dB and an OP1dB of 20~19.5 dBm.