A high performance unilateral 900 MHz LNA with simultaneous noise, impedance, and IP3 match

This paper describes a novel current-feedback LNA design with C_bc-neutralization. The resulting unilateral amplifier stage is completed with out-of-band loading for improved linearity. The proposed design method provides simultaneous noise, impedance and IP3 matching for the active device; resulting in maximum gain, linearity, isolation, and stability even at very low current levels. As verification a 900 MHz hybrid Si BJT LNA is constructed, which achieves 1.3 dB NF, 15 dB gain, 55 dB isolation, and +10dBm IIP3 with 2.5mA of collector current at V_CE = 1.5 V.