Parametric amplifier has lowest noise figure

Using a newly designed tuning cavity and an improved semiconductor diode as the amplifying medium, Bell Telephone Laboratories scientists have built a non-degenerate parametric amplifier with an over-all system noise temperature of 60 degrees Kelvin at 6 kmc, or a noise figure of about 0.9 db. This is the lowest noise figure ever achieved for a device of this type. The development was reported at the recent International Solid-State Circuits Conference in a paper by Michiyuki Uenohara.