Litton Systems, Inc.

Other

Chris L Wheeland

Guilford R MacPhail

Edward M Doyle

Kenneth F Ramacher

Michael S Worthington

Joseph C Musheno

George K Farney

John C Cipolla

Richard J Pasco

Scott A Kleinle

James L Barry

A crossed-field amplifier is provided having a cathode structure with an emitting surface which emits secondary electrons upon impingement of priming electrons, an anode vane structure surrounding the cathode and a signal input port located adjacent the anode vanes. A secondary emission material is disposed in an area proximate the signal input port for providing priming electrons in the interaction region of the amplifier. The RF input signal causes the secondary emission material to emit priming electrons for use by the cathode structure. The creation of priming electrons in the interaction area reduces irregular start-up or 'jitter' typically experienced with the amplifier at low pulse repetition frequencies.

Passive jitter reduction in crossed-field amplifier with secondary

The present invention provides a double helix coupled vane forward wave crossed-field amplifier utilizing backwall cooling and vane channel cooling in the RF slow wave circuit. Backwall channel cooling is provided for the majority of the anode vanes. Additional cooling is provided exclusively for the output vanes via individual coolant carrying passages in each output vane. The coolant carrying passages are machined into each standard double helix coupled output vane to create a vane channel in the shape of a 'U'. A tube formed in a corresponding U-shape is inserted and brazed to the machined vane. The vane assembly is then attached to the anode body of which the backwall has holes formed to accept the tubes from each vane. Divided backwall coolant channels are brazed to the outside of the anode, thereby placing in fluid communication the coolant channels to the tubes. Accordingly, coolant is cycled from a first backwall channel, through the output vanes and through the majority of the circumference of the anode via a second backwall channel, and back into the first backwall channel through a conduit and the vanes of the anode are thus preferentially cooled.

Preferentially cooled forward wave crossed-field amplifier anode

The present invention provides a double helix coupled vane forward wave crossed-field amplifier utilizing individually cooled vanes in the RF slow-wave circuit. Specifically, a double helix coupled vane is machined to create a channel in the shape of a 'U' on one side of the vane. A vane coolant tube formed in a corresponding U-shape is inserted and brazed to the machined vane. The vane assembly is then attached to the anode body of which the backwall has holes formed to accept the coolant tubes from each vane. Divided backwall coolant channels are brazed to the outside of the anode, thereby placing in fluid communication the coolant channels to the vane coolant tube. Accordingly, coolant is cycled through each vane tube and individual vanes of the anode are thus cooled.

Internally cooled forward wave crossed field amplifier anode vane

A crossed-field amplifier (CFA) includes a cylindrical cathode having an emitting surface coaxially disposed within an annular anode structure. The cathode has at least one circumferential groove disposed in the emitting surface. The grooves are relatively deep in comparison with their width. The grooves provide a phase smoothing of the rotating electron cloud spokes operative during crossed-field interaction. CFA noise is reduced by removal of the out-of-phase electrons. Due to their deeply cycloiding paths, these out-of-phase electrons become trapped in the grooves within a region generally shielded from the electric field of the CFA.

Phase smoothing cathode for reduced noise crossed-field amplifier

There is provided a miniature high gain forward wave crossed-field amplifier wherein the anode slow wave structure includes double helix coupled vanes having a predetermined pitch such that the distance between the plane of symmetry of each vane is substantially narrow as compared with the thickness of each vane. The vanes also having a predetermined length and height, the height being greater than one half of the length. The wires of the double helical coils has a cross-sectional thickness which is at least one order of magnitude less than the plane of symmetry diameter of each turn of the coils. The distance between the outer diameter of each coil along the transverse face of each vane is quite large. The pitch ratio of the vanes is less than one half of the thickness thereof. Samarium cobalt magnets are used having annular end pieces which form the walls of the vacuum chamber. A high gain of 18 to 22 dB in a volume of approximately 50 cubic inches and a weight of less than 10 pounds is achieved.

High gain miniature crossed-field amplifier

In a forward wave low noise cross-field amplifier a slow wave structure is disposed about a predetermined portion of the cathode. The slow wave structure of the cathode is accurately proportioned and spaced to have a dispersion curve near to the dispersion of the slow wave structure of the anode to permit cross-coupling of the RF input from the slow wave structure of the anode to the slow wave structure of the cathode.

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Winfield, PA, United States of America

Chris L Wheeland