Zusammenfassung
Readout amplifiers with high bandwidth and extremely low power dissipation
at liquid helium temperature for various superconducting detectors
(e.g. SNSPD, HEB and MKID) are necessary to increase the small detector
output signals. Different types of cryogenic amplifiers were developed
for these applications. The required combination of low noise, large
bandwidth, high voltage gain and low power consumption is a driving
force for an on-going process of improvements. In this paper, the
developments of cryogenic low power hybrid amplifiers, which are
based on commercial p-HEMT transistors, will be reported and discussed.
In addition, simulation and measurement results of the first developed
monolithic microwave integrated circuit (MMIC) amplifier for low
power operation will be presented. The MMICs are based on a metamorphic
HEMT technology and are realized on a \$3times 1.5 \rm mm\\^\2\\$ area.
First measurements at room temperature showed a bandwidth of 0.3
GHz up to 9 GHz with a gain of 23 dB at 90 mW and 1.3 GHz up to 8
GHz with 20 dB of gain at 42 mW, respectively. The power consumption
could be reduced by cooling the devices down to 7.2 K. At almost
identical bandwidths, the measured gain decreased to 10 dB at 22
mW and 15 dB at 9.5 mW.
Nutzer