We propose a Ka-Band klystron amplifier for use in CubeSats. It will operate at 35.7 GHz, have 400 MHz of bandwidth, and output at least 32 watts of saturated power. Small signal gain will exceed 35 dB. In its final form, it will occupy a space 0.4-inch diameter and less than 0.5-inch in length. The combination of small size, high power, and high frequency obviate the use of solid state power amplifiers. Klystrons are the only technology that can be miniaturized to this degree. We propose an innovative construction technology that involves electrostatic focusing, glass insulator fastening of tube elements, a telescoping collector, and a highly loaded scandate cathode with integral focus electrode capable of 50 A/cm2. In Phase I we will build full performance prototypes. e beam inc. is the world's leader in innovative miniature cathode assemblies, electron guns, and vacuum electron devices generally. It has long promoted the transfer of cathode ray tube construction technology to other devices as a way to reduce size, mass, and cost. It has successfully done this with microwave amplifiers, terahertz mass spectrometers, and x-ray tubes. Some of these designs have been deployed in space.