Abstract: An electron beam tube apparatus comprises a plurality of electron beam tubes having a common output cavity. Power is coupled to the common cavity from the resonant cavities of the beam tubes, and is then fed to an output line. This arrangement permits the outputs of two or more beam tubes to be combined in a compact arrangement with little rf power loss. Previously, the signals from the output lines of respective beam tubes were combined. The output line may be transmission line or waveguide. The means for coupling signals between the cavities may comprise loops or irises, both of which may be selectively adjustable.

Abstract: An electron beam tube apparatus comprises a plurality of electron beam tubes having a common output cavity. Power is coupled to the common cavity from the resonant cavities of the beam tubes, and is then fed to an output line. This arrangement permits the outputs of two or more beam tubes to be combined in a compact arrangement with little rf power loss. Previously, the signals from the output lines of respective beam tubes were combined. The output line may be transmission line or waveguide. The means for coupling signals between the cavities may comprise loops or irises, both of which may be selectively adjustable.

Abstract: An r.f. radiation absorbing material able to hold off a 30 to 40 kV voltage difference is described as formed by a silicon rubber loaded with ferrite particles. The material is used to reduce self-oscillation in amplifiers.

Abstract: In an electron beam tube such as a klystron, a vacuum seal comprises a ceramic cylindrical wall on which are brazed metal rings which are welded to flares and fixed to electrodes and of a collector. Ceramic rings and are located between the metal ring and the electrodes. The cylindrical wall includes inner flanges which overlap the inner peripheries of the metal rings hence reducing the likelihood of arcing occurring between them and other parts of the arrangement at different potentials. In other embodiments of the invention, the ceramic rings are extended to shield the inner edges of the metal rings or a separate ceramic tube is positioned within the metal rings to provided shielding.

Abstract: In a klystron, or other device which uses modulation of an electron beam to produce amplification of an applied high frequency signal, a collector is used to receive electrons of the beam after the amplified signal has been coupled from the device. Any secondary electrons produced by the impact of high energy electrons on the collector surface are prevented from returning back along the klystron by a periodic magnetic field produce by magnets which coaxially surround the collector.

Abstract: An amplifying arrangement employs both density and velocity modulation of an electron beam in order to produce amplification of a high frequency signal. In one embodiment, density modulation is produced at the cathode region, a first carrier signal being applied between a cathode and a modulation grid to produce bunching of electrons. The density modulated electron beam is then velocity modulated at a first resonant cavity. It is preferred that the first carrier signal is twice the frequency of the carrier signal producing the velocity modulation. The arrangement may be such that, at the final resonant cavity, adjacent electron bunches produced by density modulation combine, thus giving a high efficiency amplifying arrangement.

Abstract: An electron beam tube arrangement has an output cavity resonator circuit which includes a first output cavity, a second output cavity being coupled thereto by means of a coupling loop. The coupling loop is located in the first cavity and connected to said second cavity. In one embodiment of the invention, the second cavity also contains a coupling loop which is electrically connected to that in the first output cavity.

Abstract: An amplifying arrangement includes a klystron in which an electron beam interacts with a high frequency signal to produce a modulated amplified signal. The high frequency signal is maintained at a substantially constant amplitude and modulation of the amplified signal is provided by controlling the electron beam current.

Abstract: Klystrons are inherently non-linear and have an amplification characteristic which is frequency dependent on both signal amplitude and beam current. This may be compensated for by applying suitable correcting signals to a beam controlling electrode of the klystron thereby changing its electron beam current over the whole excursion of a modulating signal. A klystron arrangement in accordance with the invention is particularly suitable for use in a television transmitter, enabling full time modulation to be carried out with a significant improvement in the operating efficiency of the klystron.

Abstract: This invention provides a klystron amplifier arrangement having means for producing a radial component of magnetic field tending to direct beam electrons out of their path from the electron gun to the collector electrode of the kylstron. By suitably choosing the strength of the radial component of magnetic field generated undesired slow electrons in the beam will tend to be deflected, while the relatively fast electrons will be substantially unaffected.The radial component of magnetic field may be axially asymmetrical or symmetrical and may be generated in a variety of ways, for example, by means of magnetic material introduced into the field region of the normally provided main solenoid or by the use of an auxiliary winding. The magnetic material may form at least part of a cylinder or cylinders surrounding the beam path, for example, if provided as at least part of a drift tube or a water jacket. Any auxiliary solenoid may for example, be wound around a cooling jacket surrounding the beam path.