Litton Systems, Inc.

Other

Guilford R MacPhail

Chris L Wheeland

John C Cipolla

Gregory T Schaeffer

Edward M Doyle

Joseph C Musheno

James L Barry

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

The present invention discloses an enhanced secondary electron emitter cathode suitable for use in a typical crossed-field amplifiers. The emitter surfaces of the cathode are formed into protuberances or knurls. The cathode's secondary emission characteristics are enhanced by providing protuberances with more surface area for electrons to bombard and for electrons to be emitted from. The protuberances increase the variety of angles of incidence of bombarding electrons thereby increasing the probability that bombarded electrons can escape the cathode's surfaces.

Enhanced secondary electron emitter

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.

Low noise crossed-field amplifier

An improvement to an existing crossed-field amplifier is shown which includes the replacement of an existing thermionic emitter with a larger platinum emitter. The platinum emitter is cooled from a surface opposite to the surface upon which a high voltage is applied to permit the form of the existing crossed-field amplifier to be maintained.

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Williamsport, PA, United States of America

Guilford R MacPhail