Patent ID: 8362958

Claim:
An aperture antenna for transmitting a circularly polarized signal, comprising: an antenna substrate, having a first surface and a second surface; an antenna ground layer, disposed on the second surface, wherein the antenna ground layer has an aperture, the aperture has a feed portion, a signal turning point, a first edge and a second edge, the first edge connects the feed portion to the signal turning point in a first direction, and the second edge connects the feed portion to the signal turning point in a second direction, the first direction is opposite to the second direction, and when the aperture antenna transmits the circularly polarized signal, a traveling wave travels on the first edge, and at least one standing wave is formed on the second edge; and a feed conductor, passing the feed portion and corresponding to aperture, wherein the aperture is circular, the aperture has a sector notch formed on a circumference thereof, and the signal turning point is located on a tip of the sector notch.