RF Frequency:                             0.001 to 1.5 GHz

Gain @ 20K:                                44dB ± 1dB (0.3-1.5 GHz), typical   > 30 dB  (.001 to 5 GHz)

Noise temperature @ 20 K:      <6K .001 to 1.5 GHz,  < 10K to  5 GHz

Noise figure @ 20 K:                 < 0.11 dB, typical .0001 to 1.5 GHz

Noise figure @ 300K                 <1.5dB from .0001  to 5 GHz

IRL (-20log | S11 |)                    > 15 dB (0.1 –  1.5 GHz),

ORL (-20log | S22 |)                  > 15 dB (0.1 –  1.5 GHz)

Operating temperature:           4.2 K- 320 K

DC power @300K                     4V, 21mA, 84mW

DC power @ 17 K:                     3V, 12mA, 36 mW

Output power for                      -3 dBm

     1 dB compression

Safe input power level              < 0 dBm


The CITLF1 a SiGe low noise amplifier intended for extremely low noise cryogenic applications. The amplifier utilizes resistive feedback to achieve good input match (S11) and high gain stability. 

The amplifier is optimum for the frequency range of 0.1 MHz to 1500 MHz but has high gqin and low noise to 5 GHz.


It  is powered from a single positive DC supply which is optimum at 3V but can be reduced to as low as 1.1V for low power dissipation. Application of up to 6V will not damage the amplifier. It is recommended that the power supply for the amplifier be current limited to 100mA.  A series resistor may be used. For example 150 ohms to a +5V supply will provide 3V, 13mA when the amplifier is at 20K.


The amplifier offers an optional DC bias tee for an external device connected to the amplifier input. The bias tee is formed by two 20K resistors connected to the input; one can be used as a source of current and one the sense the voltage across the external device. Voltages applied to the bias tee have no effect on amplifier operation. This option is available in a 5K or 20K bias tee.


The amplifier is 20.7mm x 15.9mm x 8.7mm excluding connectors with input SMA at left and output SMA at right as shown above. For more information and complete specs, please download the pdf data sheet on the left.

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