Design and Performance of Cryogenically-Coolable Ultra Low Noise, L-Band Amplifier

The design, realization and measurement of an ultra low-noise, cryogenically-coolable, L-band amplifier for radio astronomy applications are described. The amplifier exhibits 3 K (0.045 dB N.F.) average noise temperature over 600 MHz. bandwith with 36 dB of gain at ambient temperature of 12.5 K and 2 K average noise at physical temperature of 4.2 K. Excellent agreement between measured and predicted results verifies the validity of a recent published wideband model of a FET for L-band frequencies.