A Frequency and Bandwidth Reconfigurable 3–6 GHz Cryogenic SiGe BiCMOS LNA with a Power Consumption of ≤ 2.9 mW

A 3–6 GHz reconfigurable SiGe cryogenic low-noise amplifier has been designed, fabricated, and tested. The integrated circuit features a broadband input-stage followed by a pair of buffered reconfigurable second-order systems. When characterized at a physical temperature of 15K and configured for a broadband response (3–6 GHz), we find that it provides in excess of 35 dB of gain while achieving an average noise temperature of 4.3K from 3–6 GHz and dissipating 1.8mW. By changing the states of the digitally controllable second-order systems and on-chip digital-to-analog-converter-based bias generators, we show that the amplifier can be tuned in both bandwidth and center frequency while maintaining similar performance specifications to those achieved in the broadband mode of operation. In all cases, the power consumption of the amplifier is lower than 2.9mW. To the best of the authors' knowledge, this is the first digitally programmable cryogenic low-noise amplifier reported to date.