1. An antenna structure comprising: a planar dipole antenna comprising a first electrically conductive disc defining a first dipole antenna element, and a second electrically conductive disc defining a second dipole antenna element in parallel with and spaced apart from the first dipole antenna element; and a dual-line antenna feed structure connected to the planar dipole antenna and comprising a first conductor electrically connected to the first conductive disc adjacent a peripheral edge thereof, and a second conductor electrically connected to the second conductive disc adjacent a peripheral edge thereof.