Continuous corrugated waveguide and method of producing the same

A method of microwave transmission comprising transmitting microwaves through an elongated waveguide extending between two spaced points and comprising a corrugated tube having at least a first corrugated side intersecting at an angle with a second corrugated side forming at least first and second sets of corners, each side including a plurality of first sections and a plurality of second sections spaced from said first sections, the ends of said second sections of said first side being joined with the ends of said second sections of said second side to form a portion of the corners, another portion of each corner being formed by a first section of one of said sides foreshortened by a predetermined amount dependent on the angle of intersection and the depth of the corrugation in said sides, the end of said foreshortened first section intersecting a said first section of the other side at a distance from the end of that section, the portion of said foreshortened section removed from the extent of that section being folded back double along the corresponding first section of the other side from the end of that other first section back to the place where the end of the foreshortened section intersects that corresponding first section of the other side.

A waveguide formed of a continuous flat strip of electrically conductive metal, said strip being formed into a continuous length of a coilable corrugated tube of a rectangular cross-sectional shape having intersecting walls with one pair of parallel sides of the rectangle being substantially longer than the other pair of parallel sides, and tube having a substantially uniform wall thickness along the entire length and around the entire periphery thereof, the intersecting walls of said tube having transverse corrugations along crest and root lines that form a substantially constant perimeter length around any cross-section of the corrugated tube taken perpendicular to the axis of the tube at any point along the length of the tube, the depth of the corrugations being substantially smaller than the internal dimensions of the tube and substantially equal on all sides of the tube.

A continuous length of coilable corrugated waveguide of rectangular cross-sectional shape, said waveguide comprising

• (a) a continuous flat strip of electrically conductive metal formed into a tube with approximately a rectangular cross-sectional shape with one pair of parallel sides of the rectangle being substantially longer than the other pair of parallel sides, and with the longitudinal edges of the strip joined to each other, said strip having a thickness of from 0.01 inch to 0.05 inch,
• (b) the walls of said tube being transversely corrugated to form corrugations of adjacent intersecting walls which are offset at their intersection so that the crests of the corrugations of one of the intersecting walls meet the roots of the corrugations of the other wall and with the depth of the corrugations being substantially smaller than the internal dimensions of said tube and substantially equal on all sides of the tube, the wall-intersection shape of the longitudinal unobstructed interior being a sharp angle and the exterior including a zigzag crest connecting the ends of the corrugations crests of the intersecting walls.

A method of microwave transmission comprising transmitting microwaves through an elongated waveguide extending between two spaced points and comprising a continuous flat strip of electrically conductive metal formed into a continuous length of a coilable corrugated tube of a rectangular cross-sectional shape having intersecting walls with one pair of parallel sides of the rectangle being substantially longer than the other pair of parallel sides, said tube having a substantially uniform wall thickness along the entire length and around the entire periphery thereof, the intersecting walls of said tube having transverse corrugations along crest and root lines that form a substantially constant perimeter length around any cross-section of the corrugated tube taken perpendicular to the axis of the tube at any point along the length of the tube, the depth of the corrugations being substantially smaller than the internal dimensions of the tube and substantially equal on all sides of the tube.