Methods, systems, and devices for wireless communications are described. An antenna structure for wideband coverage may include a first bowtie antenna disposed in a first plane. The first bowtie antenna may be, for example, an elliptical bowtie antenna or a triangular bowtie antenna. The antenna structure may also include a plurality of additional bowtie antennas, each of the plurality of additional bowtie antennas disposed in a different plane parallel to the first plane. The first bowtie antenna and the plurality of additional bowtie antennas may be stacked in a first direction perpendicular to the first plane to form a bowtie antenna stack. The antenna structure may include a plurality of bowtie antenna stacks. The antenna structure may also include a staggered conductive wall.