Abstract: An electrode of an inductive output tube (IOT) is provided with channels for guiding cooling fluid. In one aspect of the invention, the channels are in a confronting relationship with a jacket surrounding the electrode and spaced from the electrode so as to define an interior region. Cooling fluid such as oil is circulated in the channels in fluid communication with the interior region, providing an escape mechanism for trapped bubbles in order to prevent localized heating of the electrode. In another aspect of the invention, the channels form multiple intersecting helical patterns of different pitches, with the steeper-pitched channels providing a more direct escape route for the bubbles.

Abstract: An overmoded distributed interaction network is provided that generates high peak and average RF power amplification at high frequencies. A series of overmoded cavities are bounded by parallel or concentric grids that may be separated by metallic spacers adapted to function as a photonic bandgap circuit to suppress competing electromagnetic modes. The selected electromagnetic modes have wavelengths much shorter than the lateral dimension of the grids, allowing the beam-wave interaction to be distributed transversely for improved interaction efficiency. The grids may optionally be slotted and arranged to provide a serpentine traveling wave tube configuration.

Abstract: Electron sources for a cathodoluminescent lighting system are disclosed. An electron source is a broad-beam reflecting-type electron gun having a cathode for emitting electrons and a reflector and/or secondary emitter electrode and no grids. An alternative electron gun has a cathode having a heater welded to a disk, the disk having an emissive surface on a side facing a dome-shaped defocusing grid and an anode. A lighting system incorporating the electron sources has an envelope with a transparent face, an anode with a phosphor layer to emit light through the face and a conductor layer. The system also has a power supply for providing from five to thirty thousand volts of power to the light emitting device to draw electrons from cathode to anode and excite a cathodoluminescent phosphor, and the electrons transiting from cathode to anode are essentially unfocused. A power-factor-corrected embodiment is also disclosed.

Abstract: An inductive output tube (IOT) operates in a frequency range above 1000 MHz. An output window may be provided to separate a vacuum portion of the IOT from an atmospheric pressure portion of the IOT, the output window being surrounded by a cooling air manifold, the manifold including an air input port and a plurality of apertures permitting cooling air to move from the port, through the manifold and into the atmospheric pressure portion of the IOT. The output cavity may include a liquid coolant input port; a lower circular coolant channel coupled to receive liquid coolant from the liquid coolant input port; a vertical coolant channel coupled to receive liquid coolant from the lower circular coolant channel; an upper circular coolant channel coupled to receive liquid coolant from the vertical coolant channel; and a liquid coolant exhaust port coupled to receive liquid coolant from the upper circular coolant channel.

Abstract: The disclosure relates to a radiofrequency generator including an Inductive Output Tube with an electron gun followed by an anode, the gun being raised to a high voltage in use, means producing an input radiofrequency signal and means of transmitting it to said IOT such that it provides an output signal whose power is amplified compared to said input signal, wherein said means producing said input radiofrequency signal, said means transmitting it to said IOT and said gun are confined in an electrostatically screened enclosure that is electrically isolated from the potential of the anode and can be raised to a high voltage, said gun receiving its high voltage from said screened enclosure. The invention is applicable to very high power radiofrequency generators.