Superdirective metamaterial-inspired electrically small antenna arrays

A new electrically small antenna design based on a metamaterial-inspired structure driven by an electrically small monopole antenna is presented. This antenna of λ
₀
/19×λ
₀
/19 size works in the UHF band and offers a simulated efficiency of 75%, with an average maximum gain of 0.86dB and a directivity of 2.12dB in the matched bandwidth of 5.2MHz. This antenna is then used in a compact array of two identical elements in order to achieve a higher directivity. Two arrays are compared: one with two driven elements and a parasitic array with only one of the two elements driven. The design details, simulated and measured radiation characteristics of the antenna system and antenna arrays are reported.