| 摘要 |
An antenna, or a method of making an antenna, comprises: an insulating substrate 12 with an axial passage 12B extending there through and a three dimensional antenna element formed on the surfaces of the substrate 12. An end region 12P of the substrate includes recesses 18 on opposite sides of the axial passage 12B and a feed board structure 16 is arranged to extend through the passage. The feed board transmission line structure 16 includes an end region which extends perpendicular to the axis of the substrate 12 and beyond the perimeter of the passage 12B and is arranged to be located within the said recesses 18 in the end region 12P of the substrate 12. The recesses 18 may be plated with a conductive material and tapered towards the same width as the thickness of the edges 16PE of the feed circuit board 16 such that the said board can be securely located and connected within the recesses using a solder reflow technique. The depth dG of the recesses 18 may be varied to adjust the length of certain conductive pathways relating to the linearly polarized radiation produced by the coaxial monopole mode of operation of the antenna. The antenna also provides circular polarized radiation from a rotating dipole mode of operation. The antenna may operate at frequencies in the region of 1575 MHz and 2450 MHz. |
