Flat antenna for circularly-polarized wave

摘要

A ground conductor plane 1 and an excitation electrode 2 are provided substantially in parallel with each other. Two electrodes 3a and 3b for respectively radiating a linearly-polarized wave are provided substantially in parallel with the ground conductor plane 1, with the excitation electrode 2 interposed therebetween. The radiation electrodes are provides in close proximity to the excitation electrode 2 such that one end of each of the radiation electrodes 3a and 3b establishes capacitive coupling with respect to the excitation electrode 2. The other ends of each of the radiation electrodes 3a and 3b are grounded such that the directions in which electric fields are to be excited becomes substantially orthogonal to each other. For instance, a feeding section 4 is provided in flush with the ground conductor plane 1 and is electrically connected to the excitation electrode 2 via a feeding electrode 5.