Compact Fully Metallic Millimeter-Wave Waveguide-Fed Periodic Leaky-Wave Antenna Based on Corrugated Parallel-Plate Waveguides

A compact fully metallic millimeter-wave (MMW) periodic leaky-wave antenna (LWA) based on corrugated parallel-plate waveguides with high radiation efficiency and low machining complexity is presented in this letter. The LWA consists of a smooth plate and a corrugated plate that integrates the corrugation for slow-wave transmission line and the radiating slots. By introducing two different elements into one radiating unit, the open stopband effect is improved and the broadside scanning is realized. As an experimental verification, a prototype in Ka-band is designed, fabricated, and measured. The scanning beams with an angular range of 48° (from -42.5° to 5.5°) and the peak gains between 11.9 and 16.0 dBi are obtained in the frequency range from 28 to 40 GHz. The radiation efficiency is higher than 85%. The results indicate its application potential in the MMW imaging and radar systems.