There is an increased need for high-power UHF microwave amplifiers for scientific, medical, industrial, broadcast and military applications with improved overall efficiency- Existing amplifier technology can provide up to a megawatt of power with electronic efficiencies in the range from 65% to 70% for a single amplifier, and in some special cases efficiencies in the mid 70% range- However the power consumed by ancillary hardware is generally not included in these efficiency values; i-e-, in the case of vacuum electronics, the electromagnet and cathode filament- The goal of this effort is to provide a high-power microwave amplifier within the UHF frequency band with overall efficiencies of 80% or higher, with power levels approaching a megawatt from a single device- We are proposing an advanced Inductive Output Tube (IOT) meet these challenging efficiency requirements- Key to meeting or exceeding the 80% efficiency is our unique, proprietary compact IOT output cavity, which is optimized for maximum energy extraction and has shown in initial simulations electronic conversion efficiencies as high as 81%- The compact footprint of this cavity creates new opportunities for permanent magnet focusing, eliminating the power consumed by conventional electromagnets-
