An integrated pressurized electronic power amplifier circuit including a plasma cathode structure and beam focusing approach leading to an electron beam, an interaction region; an input signal line for conducting an input signal into the interaction region; an output signal line for conducting an output signal from the interaction region; a collector for the electron beam; and an envelope for maintaining a pressurized ambient and a substrate for selected spatial alignment and thermal management; and wherein the plasma cathode structure generates a plasma as a source of electrons. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.