Efficient, metamaterial-inspired loop-monopole antenna with shaped radiation pattern

A new family of metamaterial-inspired monopole antennas is reported. Split-ring resonator (SRR) is introduced into the near field region of a monopole antenna. Four configurations are proposed by changing the position of the slot of the SRR. In each case, we obtain a new behavior and a new resonance frequency, in addition to that of the monopole. The results are presented for the return loss, efficiency, surface current and radiation pattern. Four prototypes are fabricated and measured. Good agreement between numerical and experimental results is demonstrated.