A Semi-Analytical Solution of a Tapered Half-Mode Substrate-Integrated Waveguide With Application to Rapid Antenna Optimization

A semi-analytical solution for the input reflections, inner field distribution and radiated fields for a wideband traveling-wave antenna based on a tapered half-mode substrate-integrated waveguide (HMSIW) is proposed in this paper. The analysis validates the operation mechanism for this type of traveling-wave antenna which exhibits omni-directional radiation properties with horizontal polarization (magnetic dipole). The derived expressions allows the design and efficient optimization of different antennas towards fulfilling various predefined specifications of reflection coefficient and operating bandwidth. The antenna utilizes a wideband transition from coaxial cable to a HMSIW, which is also considered in the model to provide highly accurate semi-analytical results. Utilizing the proposed method, three antennas of different specifications have been optimized, manufactured and tested. The analysis, simulation and measurement results show good correspondences, which verifies the design process and demonstrates the versatility of the concept.