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

This paper presents a W-band (75-110 GHz) frequency-scanning leaky-wave antenna 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 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 3D 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 75.4GHz to 79.4GHz, equivalent to a high scanning rate of 9.68°/%BW. In simulation, when operated from 76.5GHz to 81.5GHz, 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.