Investigation of Radiation Efficiency and Bandwidth of Electrically Small MNG ZOR Metamaterial Antenna

Abstract

In this paper, the radiation efficiency and fractional bandwidth of an electrically small zeroth order resonance (ZOR) antenna based on mu-negative (MNG) metamaterials were theoretically investigated. To investigate the radiation efficiency and bandwidth of the electrically small antenna, various types of MNG ZOR antennas such as a meander line inductor and a spiral inductor with different current path have been designed. The equivalent circuits of MNG ZOR antennas are derived for theoretical analysis of an antenna. The parameters of antenna such as radiation resistance and dissipated loss have been obtained by the equivalent circuit of the MNG ZOR antennas. The dissipated loss and radiation resistance were affected by the current distribution of meander line and the direction of current path of the antenna. It is confirmed that both the radiation efficiency and bandwidth of the MNG ZOR antenna can be improved when the cancellation of current on the antenna is minimized if the losses are assumed to be the same.