Broadband MMIC amplifier for superconducting single photon detector readout in a cryogenic environment

This paper presents the design and performance of two broadband amplifiers dedicated to the amplification of a superconducting single photon detector (SSPD) signal. Both the sensor and the amplifiers are going to be operated at liquid helium temperature. The MMICs were realized in a 100 nm metamorphic HEMT technology. At cryogenic temperature 23 dB of gain are achieved from 0.3 GHz to 9 GHz for the first amplifier, the second amplifier has a significantly reduced power consumption at the cost of a smaller bandwidth, which is 1.3 GHz to 8 GHz with 20 dB of gain.