CC BY 4.0 UnportedIvanov, Boris I.Volkhin, Dmitri I.Novikov, Ilya L.Pitsun, Dmitri K.Moskalev, Dmitri O.Rodionov, Ilya A.Il'ichev, EvgeniVostretsov, Aleksey G.2022-03-162022-03-162020https://oa.tib.eu/renate/handle/123456789/8246https://doi.org/10.34657/7284A broadband low-noise four-stage high-electron-mobility transistor amplifier was designed and characterized in a cryogen-free dilution refrigerator at the 3.8 K temperature stage. The obtained power dissipation of the amplifier is below 20 mW. In the frequency range from 6 to 12 GHz its gain exceeds 30 dB. The equivalent noise temperature of the amplifier is below 6 K for the presented frequency range. The amplifier is applicable for any type of cryogenic microwave measurements. As an example we demonstrate here the characterization of the superconducting X-mon qubit coupled to an on-chip coplanar waveguide resonator. ©2020 Ivanov et al.; licensee Beilstein-Institut.License and terms: see end of document.enghttps://creativecommons.org/licenses/by/4.0/620540HEMT amplifiercryogenic low-noise amplifierhigh-electron-mobility transistor (HEMT)microwave cryogenic amplifiermicrowave superconducting circuit readoutsuperconducting qubit readoutArticle