Miniaturisation of Ε-negative transmission line based zeroth-order resonator antenna

A previously presented ε-negative transmission line-based zeroth-order resonator antenna structure rescaled to operate at the 2.45 GHz ISM band. The antenna structure is investigated and its feeding network is minimised by using a properly located coaxial. Additionally, a design parameter capable of influencing the radiation pattern is explored. Moreover, this parameter can also reduce the size of the structure. The final antenna structure appears to be better or at least competitive to the best metamaterial-based antennas in terms of size-bandwidth performance.