Abstract: A continuous transverse stub element array structure which forms a coaxial geometry formed from a plurality of cylindrical segments, wherein each of the cylindrical segments has a rim at a top end and a bottom end, wherein each rim extends transversely away from the cylindrical segment relative to a longitudinal axis thereof to thereby form a stub element, wherein the individual cylindrical transverse stub elements are aligned end-to-end to thereby form a coaxial cable structure which surrounds a central core material. The series of these stubs form reactive or radiating elements for microwave, millimeter-wave, and quasi-optical filters and antennas. Purely reactive elements are formed by leaving the conductive coating on the terminus of the stub elements, whereas radiating elements are formed when stub elements of moderate radius are opened to free space.