Millimeter-wave Polymer Rod Based Leaky-Wave Antenna Design with Open Stopband Suppression

In this work, a dielectric waveguide-based leaky-wave antenna for operation in millimeter-wave frequency is presented. The proposed antenna design features a periodic array of annular metal rings realized on a thin substrate that is wrapped around a low-permittivity Teflon rod waveguide, thereby leading to a frequency-based scan of its directive main lobe of radiation. A novel architecture of capacitive compensation in the perturbation elements is proposed, which resolves the generic limitation of open-stopband suppression of radiation from the dielectric rod-based leaky-wave antenna. The presented experimental prototype of the antenna design shows a measured gain in excess of 10 dBi over a wide operational bandwidth from 28 GHz to 40 GHz along with an input matching better than 15 dB. Simultaneously, measurements show the directive beam scanning over more than 25 degrees from the broadside axis along both the forward and backward directions. Necessary theoretical analysis is presented to support these observations and the working principle of the antenna along with the dielectric waveguide in the Ka-band. The proposed antenna design can be scaled to higher frequencies owing to its robust geometry, relaxed low-cost assembly, and ease of manufacturing.