A W-Band Frequency-Scanning Leaky Wave Antenna Based on a Composite Right/Left-Handed Waveguide for Rapid Beam Scanning

This article presents a W-band (75–110 GHz) frequency-scanning leaky wave antenna (LWA) with backward-to-forward rapid beam-scanning capability. The design takes advantage of the low-loss and high-dispersion features of an air-filled composite right/left-handed (CRLH) metallic waveguide. Equivalent circuit modeling and a detailed design procedure are presented to facilitate the analysis and design. The design method is validated by a prototype antenna using 3-D printing technology. Measurement results are consistent with simulated ones and show a wide field of view (FoV) from −15° to +35° when the radiated frequency is swept from 75.4 to 79.4 GHz, equivalent to a high scanning rate of 9.68^◦ /%BW. In simulation, when operated from 76.5 to 81.5 GHz, the FoV can cover from −30° to +50° , which translates to a scanning rate of 12.64^◦ /%BW. To the best of the authors’ knowledge, the presented antenna achieves the highest scanning rate in the W-band. The presented design may be a good candidate for millimeter-wave imaging applications that require low loss and rapid beam scanning, including automotive radars.