Miniaturized Circular-Waveguide Probe Antennas Using Metamaterial Liners

作者：Pollock Justin G^*; Iyer Ashwin K

来源：IEEE Transactions on Antennas and Propagation, 2015, 63(1): 428-433.

DOI：10.1109/tap.2014.2367551

• Circular waveguides
• epsilon-near-zero
• inhomogeneous waveguides
• metamaterials
• miniaturization
• negative permittivity
• open-ended waveguide probes

This work presents the radiation performance of open-ended circular-waveguide probe antennas that have been miniaturized by the introduction of thin metamaterial liners. The liners introduce an mode well below the natural cutoff frequency, which provides substantial gain improvements over a similarly sized waveguide probe. A new feeding arrangement employing a shielded-loop source embedded inside the miniaturized waveguide is developed to efficiently excite the mode and avoid the excitation of other modes across the frequency-reduced band while maintaining the antenna's compactness. A metamaterial-lined circular-waveguide probe antenna operating over 42% below its natural cutoff frequency is designed to provide a radiation efficiency of up to 28.8%. A simple, printed-circuit implementation of the metamaterial liner based on inductively loaded wires is proposed and its dispersion features are discussed.

• 出版日期2015-1