Aperture-miniaturized antenna loaded with split ring resonator array

In this paper, a novel antenna having a miniaturized aperture is proposed. The substrate including a split-ring resonator (SRR) array has been inserted into a size-reduced open-ended waveguide. For a low return loss and high radiation efficiency, the ring arrangement has been optimized, and a stepped transition using H-plane discontinuity is proposed. The proposed antenna achieves a 70% aperture reduction compared to a conventional standard waveguide antenna. The return loss was deeply dropped at three frequencies, and a reasonable gain was presented. The aperture-miniaturized antenna can be used in many antenna applications such as near-field measurements.