A Low-Noise Amplifier

This paper describes an amplifier circuit which yields very low noise factor, consisting of a grounded-cathode triode followed by a grounded-grid triode. The combination is entirely noncritical and provides the low noise factor of a triode with the high amplification and stability of a pentode. Noise factors averaging 0.25 db at a carrier frequency of 6 Mc. and 1.35 db at 30 Mc. have been achieved. Typical circuit details are given.

[1]  Frederick V. Hunt,et al.  On Electronic Voltage Stabilizers , 1939 .

[2]  Fluctuations and electron inertia , 1941 .

[4]  H.T. Friis,et al.  Noise Figures of Radio Receivers , 1944, Proceedings of the IRE.

[5]  K. Jansky,et al.  Minimum Noise Levels Obtained on Short-Wave Radio Receiving Systems , 1937, Proceedings of the Institute of Radio Engineers.

[6]  Theoretical Gain and Signal-to-Noise Ratio of the Grounded-Grid Amplifier at Ultra-High Frequencies , 1944, Proceedings of the IRE.

[7]  M.C. Jones.  Grounded-Grid Radio-Frequency Voltage Amplifiers , 1944, Proceedings of the IRE.

[8]  G.C. Sziklai,et al.  Cathode-Coupled Wide-Band Amplifiers , 1945, Proceedings of the IRE.