Broad bandwidth, efficient, metamaterial-inspired, electrically small antennas augmented with internal non-Foster elements

Broad bandwidth metamaterial-inspired electric and magnetic antennas have been designed and characterized numerically. By augmenting their narrow bandwidth counterparts with internal non-Foster elements, active metamaterial unit cells are introduced as near-field resonant parasitic (NFRP) elements. Nearly complete matching of the entire system to a 50 Ω source without any matching network and high radiation efficiencies over their FBW_10dB bandwidths that are more than 75 times their original values have been achieved.