Abstract: A radiated mode coaxial cable comprising an outer conductor provided with a periodic aperture array, comprising a plurality (n) of apertures or aperture sets, repeated along the length of said outer conductor whereas a constant spacing s separates the left end of the first aperture of one array and the left end of the first aperture of a next array, wherein each array comprises at least 10 apertures or aperture sets, whereas the global length L (in mm) of the apertures or aperture sets is larger than (10D/n)1/2 where D is the diameter of the cable (in mm) and whereas the aperture spacing (d) in between two successive apertures or aperture sets is larger than 1.5w where w is the aperture width in the cable axis direction, and wherein the spacing s between two successive aperture arrays is selected so that ?opt.1/(??r?0,866)<s<?opt.2/(??r?1), where ?opt.1 and ?opt.