Design of gain optimized broadband low noise amplifiers at 120 GHz using SiGe technology

This paper presents the design of single-ended, double stage cascode low noise amplifiers at 120 GHz. A design methodology employing three techniques for gain enhancement of the LNA is presented. The effect of traditional emitter - degeneration technique and its feasibility for simultaneous noise and power matching is evaluated at 120 GHz. The LNAs are designed in a 250 GHz f_T and 300 GHz f_max 0.13 μm SiGe:C BiCMOS process. By employing the three design techniques the gain of the LNA is improved by almost 3.5 dB. The two stage gain optimized LNA achieves a gain of 24 dB and a noise figure of 7.2 dB. The circuit works with a supply voltage of 3.3 V and consumes less than 40 mW of power.