An aperture feed network includes a substrate having a first surface and a parallel second surface, first and second conductive traces on the first surface of the substrate, a third conductive trace on the second surface of the substrate, a conductive via extending through a thickness of the substrate, and one or more ground plane structures on the second surface of the substrate. The substrate comprises a dielectric material. The first and second conductive traces together form a differential signal line. The third conductive trace comprises a first branch and a second branch. The conductive via contacts the first branch of the third conductive trace on the second surface of the substrate and the second conductive trace on the first surface of the substrate. The one or more ground plane structures have irregular shapes.