Design and Characterization of a Variable Gain D-Band LNA for Optimized Link Budgeting for a 6G Receiver in 22FDX

This article describes the design and characterization of a fully differential <inline-formula> <tex-math notation="LaTeX">$D$ </tex-math></inline-formula>-band low noise amplifier (LNA) with a measured gain of 9.0–18.0 dB at 153.5 GHz over a 3-dB bandwidth of 10.8 GHz. A minimum noise figure (NF) of 7.9 dB is achieved, measured with the cold-noise source method using a source tuner for noise parameter extraction to enable high accurate NF measurements. The extracted noise parameters allow the source impedance sensitivity to be calculated, with an NF degradation of less than 1.2 dB demonstrated for a source reflection <inline-formula> <tex-math notation="LaTeX">$|\Gamma _{s}|\leq 0.3$ </tex-math></inline-formula>. Using the back gate control of the 22-nm fully depleted silicon on insulator (FDSOI) technology enables a passive gain control range of 9 dB, reducing the NF and compression point degradation while scaling the power consumption, thanks to optimal transistor biasing. The measured LNA parameters such as gain, NF, compression, and bandwidth are applied in a link budget analyzer to verify sufficient signal-to-noise and distortion ratio (SNDR) for a 100-GBit/s receiver.