X-band monolithic variable gain series feedback LNA

摘要

A description is given of an X-band monolithic four-stage low-noise amplifier (LNA) using series feedback that has demonstrated a 1.8-dB noise figure with 33.8-dB gain and greater than 40-dB gain control capability. This design features single-gate and dual-gate FETs (DGFETs) on the same chip. Gain control is achieved without degradation of input or output VSWR (voltage standing-wave ratio). The two input stages use single-gate FETs to achieve minimum noise figure, while the output stages use DGFETs for gain control capability.