Patent ID: 7471258

Claim:
Radiating coaxial cable transmission line apparatus having high radiation efficiency, the apparatus comprising: center conductor for carrying electromagnetic waveband signals; surrounding said center conductor, a first insulator for electrically insulating said center conductor; superjacent said first insulator means for boosting bifilar-to-monofilar mode rate conversion of said signals comprising a: first helical outer conductor wound with a first helical pitch around the first insulator and a second helical outer conductor wound with a second helical pitch around said first insulator and proximate said first helical outer conductor; and surrounding said means for boosting bifilar-to-monofilar mode rate conversion, said first insulator, and said center conductor, a second insulator for insulating said apparatus from a local environment, wherein said first helical pitch and said second helical pitch are determined by an equation comprising: 1 /p 1 −1 /p 2 =1/λ where: p 1 is pitch angle for the first helical outer conductor, p 2 is pitch angle for the second helical outer conductor, and λ is approximate center wavelength for a bandwidth-of-interest.