RF Frequency:                               1 to 18  GHz

Gain @ 20K:                                  35dB ± 2dB

Noise temperature @ 20 K:       <8K at 1 to 20 GHz

Noise figure @ 20 K:                   < 0.13 dB

Noise figure @ 300K                   <1.5 dB

IRL (-20log | S11 |)                      > 0 dB (stablem all frequencies)

                                                         >10 dB at 9 to 22 GHz

ORL (-20log | S22 |)                   > 10 dB at 1 to 18 GHz

Operating temperature:             4.2 K- 320 K

DC power @300K                       1.5V, 34mA, 51mW

DC power @ 20 K:                      1.2V, 27mA, 33 mW

Output power for                        -3 dBm

     1 dB compression

Safe input power level               < 0 dBm


The CIT118  is a  GaAs HEMT cryogenic, low noise, broadband amplifier. The amplifier requires one drain voltage in the 0.6V  to 1.5V  range  and one gate voltage in the -3 V to +1 V range through terminals Vg1 and Vg2, each with 11K DC input resistance.  See the table on p. 4 of the PFD for performance vs bias voltages.  If desired the gate supply can be eliminated (open circuit  pins Vg1 and Vg2) at slightly less than optimum performance.


The amplifier may be operated at room temperature to give a noise  figure < 1,70 dB and gain < 33dB from 0.5 to 22 GHz. Note that a  more negative gate supply voltage, typically -1.5V is required at room temperature. However  the amplifier  is not damaged if the gate voltage for cryogenic operation, typically 0V, is applied at room temperature (though the gain will be low). Input and output return loss change very little from 300K to 4K. For more information and complete specs, please download the pdf data sheet on the left.