This document describes designs and techniques for directly feeding an unbalanced transmission line with a balanced antenna using Composite Right and Left Handed (CRLH) and balun structures. According to various examples, first and second radiating elements, first and second antenna structures, or first and second portions of an antenna structure can provide a left-handed (LH) mode resonance and a right-handed (RH) mode resonance. A feed port can provide an unbalanced signal, and a balun structure can be coupled to the first and second radiating elements, first and second antenna structures, or first and second portions of an antenna structure, to adapt the unbalanced signal from the feed port to a balanced signal for coupling to the first and second radiating elements, first and second antenna structures, or first and second portions of an antenna structure.