A low noise traveling wave tube amplifier packaged with integral solid state power supply and permanent magnet focusing was developed to cover the frequency band 18 to 40 GHz. The amplifier noise figure lies between 13 and 14 dB; the minimum small signal gain is 32 dB, and the gain variation is plus or minus 2.7 dB. The minimum saturated power output is + 6 dbm. The tube employs a hollow beam six anode low noise electron gun. A unique ridge waveguide coupler was developed to cover the double waveguide band. A key factor in reducing gain variation was development of an improved 'skrunching' method for the fluted glass helix support structure. The tube completes a series of four low noise traveling wave tube amplifiers covering the 0.5 to 40 GHz frequency band. (Author).

The purpose of this program is the attainment of low-noise amplification over two octaves in a single traveling-wave tube. Noise figure is to be less than 6.5 dB from 0.5 to 2.1 GHz with a minimum of three milliwatts saturated power output. The work described herein has been aimed primarily at raising the power output to the required three milliwatt level and achieving uniform gain over the full band. This has been sought through the use of a servered helix, with the output section operating with higher voltage and lower gamma than the input, or low-noise section. Good results have been obtained with this method, the power output being greater than two milliwatts over practically the entire band. It is concluded that this approach is entirely feasible technically, and that future effort will be expended applying it to reduce gain variation at an increased power level. At present, noise figure of the tube is within the specification over all of the band. (Author).