Compact Coaxial Waveguide-Based Antenna

Most waveguide antennas use hollow waveguide with arrays of slot elements, offering a simple and highly efficient structure. Coaxial waveguide allows a smaller cross-section, and using just one element, or two co-located elements, leads to a compact antenna. We present new, dual- and single-slot designs based on coaxial waveguide that are compact and wideband. The designs include a coaxial feed, and are fabricated and measured to verify their performance.