Synthesis, Simulation and Experiment of Unequally Spaced Resonant Slotted-Waveguide Antenna Arrays Based on the Infinite Wavelength Propagation Property of Composite Right/Left-Handed Waveguide

Synthesis, simulation and experiment of unequally spaced resonant slotted-waveguide antenna arrays based on the infinite wavelength propagation property of composite right/left-handed (CRLH) waveguide has been demonstrated in this paper. Both the slot element spacing and excitation amplitude of the antenna array can be adjusted to tailor the radiation pattern. A specially designed shorted CRLH waveguide, as the feed structure of the antenna array, is to work at the infinite wavelength propagation frequency. This ensures that all unequally spaced slot elements along the shorted CRLH waveguide wall can be excited either inphase or antiphase. Four different unequally spaced resonant slotted-waveguide antenna arrays are designed to form pencil, flat-topped and difference beam patterns. Through the synthesis, simulation and experiment, it proves that the proposed arrays are able to exhibit better radiation performances than conventional resonant slotted-waveguide antenna arrays.