Helical antenna with built-in duplexing means, and manufacturing methods therefor

A method for the manufacture of a helix antenna with integrated miniaturised duplexing and supply means comprising two decoupled coaxial helices, characterised in that said method comprises, for each of said helices, the following steps:

• the printing, on a plane substrate, of at least two radiating antennas designed to form a helix and of a supply structure for each helix, each supply structure being an independent, miniaturised structure for the wideband supply of said radiating strands comprising at least one hybrid coupler made out of semi-localised elements, said semi-localized elements being designed according to the following steps:
• designing said coupler with conventional distributed stripline elements, each of them having at least a λ/4 length;
• turning each of said distributed stripline elements into lumped elements, each of them being a π cell made of one capacitance C and two inductances L,L′;
• and
• turning each of said capacitances and inductances into semi-localised elements, each of said inductances being turned into a reduced width line and each of said capacitances being turned into a larger width line, each of said lines being smaller than λ/4;
• so that the space requirement of each of said supply structures is smaller than λ/4, λ being the maximum wavelength of operation of said antenna;
• and
• the winding of said substrate around a cylindrical support.

A method for the manufacture of a helix antenna with integrated miniaturised duplexing and supply means comprising two decoupled coaxial helices, characterised in that said method comprises, for each of said helices, the following steps:

• the obtaining of a cylindrical support bearing a substrate;
• the printing, on said substrate, of at least two radiating antennas designed to form a helix and a supply structure for each helix, each supply structure being an independent, miniaturised structure for the wideband supply of said radiating strands comprising at least one hybrid coupler made out of semi-localised elements, said semi-localized elements being designed according to the following steps:
• designing said coupler with conventional distributed stripline elements, each of them having at least a λ/4 length:
• turning each of said distributed stripline element into lumped elements, each of them being a π cell made of one capacitance C and two inductances L,L′;
• and
• turning each of said capacitances and inductances into semi-localised elements, each of said inductances being turned into a reduced width line and each of said capacitances being turned into a larger width line, each of said lines being smaller than λ/4,
• so that the space requirement of each of said supply structures is smaller than λ/4, λ being the maximum wavelength of operation of said antenna.