Process variation compensation of a 4.6 GHz LNA in 65nm CMOS

We present the design of a 4.6 GHz LNA in TSMC 65nm with a feedback scheme to compensate for variations across process, supply voltage, and temperature. No post fabrication efforts are required in this compensation method. The proposed method improves the variation in S₂₁ of an inductively degenerated cascode LNA from 8.75% to 1.27%, which is a reduction in variation of 85%. The presented scheme is also robust over variations in supply voltage, temperature, and process conditions. The compensation method presented can be utilized to stabilize the gain of a wide variety of amplifiers.