Abstract: A process for the manufacture of a circular helix waveguide comprising a helically wound insulated metallic wire covered with a barrier layer and forming a wound and wrapped structure itself covered by a metallic screen, wherein a metal band is shaped into a tube, the contiguous edges of the said band are welded by a high frequency current in such a way that after welding the internal diameter of the shaped tube is a few millimeters greater than the external diameter of the wound and wrapped structure, the said tube is placed around the said structure, then the said tube is shaped into a cylinder with a circular base on the said structure to constitute the said metallic screen.