Waveguide probe with size-reduced aperture using split-ring resonator array for near-field measurements

A waveguide probe with size-reduced aperture for near-field measurements is proposed. The open-ended waveguide loads the split ring resonator array. The low return loss, high efficiency, and length extension have been achieved by optimising the ring arrangement as well as adopting a double-ridged waveguide and inserting a dielectric material. The proposed probe produces 70% aperture reduction in comparison to conventionally designed probes. The return loss, radiation pattern and gain from the simulation and measurement show good results.