High‐performance balun for a dual‐polarised dipole antenna

This study proposes a detailed analysis on the operation of a high‐performance balun for a dual‐polarised dipole antenna. The main feature of this balun is to transform a coaxial feed into a differential feed which can enable very high performance for dual‐polarised configurations. First, the authors identify the key factors that allow the new balun to achieve better differential properties with respect to the feeding approach typically found in the literature. Second, they investigate the balun properties and the achievable antenna performance with extensive simulations. Next, they prototype and measure the antenna proving that very high port‐to‐port isolation and low cross‐polarisation level can be achieved over a broadband operation by means of this balun. Finally, they further investigate the operation of the balun through its physical decomposition revealing the minimum requirement to achieve high port‐to‐port isolation in dual‐polarised dipole antennas.