Harris Corporation

Bobby J Boan

Martin Schwam

William F Croswell

James A Sanborn

Amos W Morse

James A Sandborn

Marvin R Sullivan

An electrically conductive epoxy-based adhesive. The epoxy is selected from the amine curing modified epoxy family consisting of a resin that is a combination of polyglycidylaminophenyl resin and polygylcidylether of phenylformaldehyde novalac resin family, and a catalyst that is a combination of one member from the aliphatic amide family plus one member from the aliphatic polyamine family. In one embodiment includes 17 parts by weight of the resin and 10 parts by weight of the catalyst. 73 parts by weight of a mixture of properly shaped silver flake particles are added. The resulting adhesive is curable at room temperature to provide a high-temperature, high-strength, electrically conductive adhesive.

Electroconductive adhesive

An electrically conductive epoxy-based adhesive. The epoxy is selected from the amine curing modified epoxy family consisting of a resin that is a combination of polygylcidylaminophenyl resin and polygylcidylether of phenylformaldehyde novalac resin family and a catalyst that is a combination of one member from the aliphatic amide family plus one member from the aliphatic polyamine family. In one embodiment includes 17 parts by weight of the resin and 10 parts by weight of the catalyst. 73 parts by weight of a mixture of properly shaped silver flake particles are added. The resulting adhesive is curable at room temperature to provide a high-temperature, high-strength, electrically conductive adhesive.

An antenna reflector material for electromagnetic waves is comprised of knitted strands of fine diameter graphite filaments, which have been individually coated with a stress absorbing layer (e.g. a thin metallic or dielectric cladding). Because of the stress absorbing coating, the graphite fibers, which, by themselves, are inherently brittle and unable to tolerate substantial changes to their bend radius profiles, are able to be successfully knitted into a tricot mesh configuration and thereby yield an antenna surface material that possesses a near-zero coefficient of thermal expansion and a sufficiently low in-plane mechanical stiffness. After the tricot knit graphite mesh material has been formed, the cladding layer may be removed (e.g. by heat or chemically dissolved), without affecting the mechanical properties of the graphite strands of the tricot knit. The intended displacement capability of the loops of graphite strands within the knit mesh structure are retained, so that thermal inputs do not alter the performance characteristics of the graphite mesh antenna.

Mesh-configured rf antenna formed of knit graphite fibers

A waveguide-fed horn structure includes a constraining mechanism having an extremely high degree of dimensional stability over a wide thermal range. The constraining mechanism comprises a composite graphite honeycomb structure that forms a support backing for the waveguide feed and for the conductive surface sections of the horn radiator. The conductive surface of the horn radiator is supported on a first section of graphite epoxy laminate while a second section of graphite epoxy laminate supports the honeycomb backing and is bonded to the first section of laminate, thereby effectively surrounding the feed-horn structure with a thermally tolerant, physical distortion constraining support. The graphite epoxy support provides sufficient mass and mechanical stiffness to prevent performance degrading distortion of both the waveguide feed and the horn radiator surface in spite of the severe transient thermal conditions encountered in a spaceborne environment, thereby maintaining structural integrity of the components of the structure during extreme thermal cycling conditions (full sun to no sun).

Waveguide fed composite horn antenna

An improved antenna mesh material is made of gold-plated tungsten wire. Because gold-plated tungsten can be drawn to a very fine diameter (less than one mil) it results in a knit mesh having low mechanical stiffness. It also has high electrical conductivity, thereby enhancing its operation as an antenna reflector up to the higher RF frequencies (EHF). In addition, gold-plated tungsten has both sufficient tensile strength and a low coefficient of thermal expansion which enables it to maintain high reflector surface accuracy for changing thermal conditions.

Growing community of inventors

Indian Harbour Beach, FL, United States of America

Bobby J Boan