Self-Resonant Broadside-Radiating Superdirective Unidirectional Mixed-Multipole Antennas

Two 28 GHz broadside-radiating unidirectional mixed-multipole antenna (UMMA) designs are presented. These UMMAs are self-resonant metamorphoses of previously reported systems. Both versions are matched to a
$\mathbf{50} \Omega$
source. Details of their directivity, front-to-back ratio, realized gain, and radiation efficiency performance characteristics are reported. It is demon-strated that both of them are superdirective, highly efficient and have interesting bandwidths. Their intrinsic attributes surpass several recognized bounds. These results add further credence to the fact that superdirective systems with useful properties are indeed practical in contradistinction to the general perception that they are not.