Dipole with an unbalanced microstrip feed

摘要

Embodiments in accordance with the invention include a linearly polarized dipole antenna with an unbalanced microstrip feed line. More specifically, embodiments in accordance with the invention utilize a fed dipole connected to a microstrip feed line, and separated a gap distance from a parasitic dipole not connected to the microstrip feed line. When an electrical signal is input to the microstrip feed line, the microstrip feed line creates a current flow in the fed dipole which induces a nearly equal current on the parasitic dipole that is out of phase. The result is a current flow, I, in the same direction in both fed and parasitic dipoles allowing for efficient radiation of the linearly polarized dipole antenna. Embodiments in accordance with the invention eliminate the need for a balun circuit thereby reducing the size, complexity and feed loss of the feed circuit. Embodiments in accordance with the invention are effective for dipoles with relatively small ground planes.

主权项

1. A linearly polarized dipole antenna with an unbalanced microstrip feed comprising:
a substrate having a top surface and a back surface; a microstrip feed line in contact with said back surface of said substrate, said microstrip feed line having an input end for accepting an electrical signal; a ground plane having a top surface and a back surface, wherein said back surface of said ground plane is in contact with at least a portion of said top surface of said substrate, said ground plane further having a ground plane aperture in said top surface of said ground plane that exposes at least a portion of said substrate; a conductive first dipole element having a first vertical stem and a first horizontal arm, wherein a first end of said first dipole element extends through said ground plane aperture through said substrate and contacts said microstrip feed line; and a conductive second dipole element having a second vertical stem and a second horizontal arm, wherein said second vertical stem is spaced a gap distance, g, apart from said first vertical stem, and further wherein a first end of said second dipole element extends through said ground plane aperture through said substrate and is connected to said back surface of said substrate.