While the utility of solid-state electronics is undeniable, vacuum devices are here to stay. A new generation of miniaturized, high-power RF amplifiers is being developed to power the next generation of communications and military technology, and these systems need highly efficient and long-lifetime electron sources.
For instance, traveling wave tube (TWT) amplifiers, which are used in satellite communications, radar, electronic warfare, and other military systems, are very inefficient, and generate significant amounts of heat that must be dissipated. Cold cathodes have long been hypothesized to represent a solution to this problem, but prior efforts have failed to demonstrate the requisite current density. At >2.5A/cm2, Nanox field effect cathodes have exceeded the necessary power requirements, while achieving efficiency of greater than 90%. Nanox field effect cathodes will usher in a new generation of compact, high-fidelity, long life, high-efficiency traveling wave tube amplifiers.