A Wideband Omnidirectional Horizontally Polarized Traveling-Wave Antenna Based on Half-Mode Substrate Integrated Waveguide

A traveling-wave antenna based on a tapered half-mode substrate integrated waveguide is introduced in this letter. It uses a direct transition from a coaxial connector and radiates from the open side of the waveguide. The antenna exhibits a wide bandwidth, an omnidirectional radiation pattern, and horizontal polarization and can be integrated into metallic structures. The physical principle and design guidelines are summarized. A prototype of the proposed antenna has been realized and demonstrated a wide measured bandwidth extending from 6.7 to 16 GHz, with radiation characteristics corresponding very well with simulations.