Double torsion coil magnetic current antenna feeding structure

A method of manufacturing an antenna apparatus having a magnetic-current feeding structure, the method comprising:

• providing a top face that is at a fixed height from a ground plane and configured for radiating at an operating wavelength λ;
• coiling a first portion of a wire in a right-handed direction and a second portion of the wire in left-handed direction to form a conductive wire helix in the wire;
• bending an end of the wire to form an excitation stub, the coiled and bent wire forming a double torsion feeding structure;
• placing the conductive wire helix of the double torsion feeding structure at a height below the top face and above the ground plane;
• and
• passing the excitation stub to an opposite side of, but not electrically connecting with, the ground plane.

A method of magnetically feeding an antenna having a nominal operating wavelength of λ, the method comprising:

• passing a current through a conductive wire helix located at a height below a top face and above a ground plane, the helix having one half coiled in a right-handed direction and another half coiled in a left handed direction, the halves connected with each other at a middle point of the helix;
• generating, by way of the passing of the current, a magnetic current dipole in one half of the helix and a magnetic current dipole in the other half of the helix, the magnetic current dipoles constructively interfering to form a driving magnetic current dipole between the top face and the ground plane;
• and
• coupling the driving magnetic current dipole with a radiating element forming the top face to create radiating magnetic currents in the radiating element.