Miniaturised self-resonant split-ring resonator antenna

A self-resonant miniaturised antenna composed of a broadside-coupled split ring resonator (SRR) and an excitation arc-shaped monopole is presented. The size of the antenna and its resonance frequency is essentially defined by the SRR dimensions and geometry, while the input resistance at the resonance is governed by the arc length of the monopole. Numerical and experimental results are presented for an antenna configuration of 1/23.4 wavelength in diameter (ka similar to 0.134). The antenna is tuned to 50 Omega without any matching network, and its efficiency is measured to be 17.5%.