W-Band cryogenic InP MMIC LNAs with noise below 30K

In this paper, we describe two monolithic millimeter-wave integrated circuit (MMIC) low noise amplifiers (LNAs) for W-Band which have a noise temperature of 30K or better over a wide bandwidth when cryogenically cooled. The LNAs were designed and fabricated in NGC's InP HEMT MMIC process having 35 nm gate length and employing an InAs Composite Channel (IACC). A two-stage amplifier exhibits room temperature S21 gain of 15–18 dB, and cryogenic gain of 20 dB with minimum noise temperature of 25K at 95 GHz, and less than 40K noise temperature between 75–105 GHz. A three-stage amplifier exhibits 29 dB of S21 gain, and a cryogenic noise temperature below 30K over the range of 94–109 GHz. We discuss the design of the amplifiers, measured and simulated S-parameters, and cryogenic measurements. To our knowledge, these are the highest frequency and lowest noise temperatures ever reported for InP cryogenic LNAs covering W-Band.