Amplitude Tapered Leaky‐Wave Antennas in Bent Additively Manufactured Nonradiative Dielectric Waveguides

ABSTRACT In this article, we introduce an inexpensive leaky‐wave antenna (LWA) design that is simple to fabricate and that is based on a nonradiative dielectric waveguide (NRDWG) platform. Although NRDWG based LWA designs have been demonstrated, these works have focused on coupling a fast wave propagating within the dielectric to a longitudinal slot located at some offset distance from the dielectric which necessitates the fabrication of new metallic parts should the design requirements of the LWA need to be changed. Therefore in this work we show that it is also possible to couple the fast wave directly to free space through a slot cut directly above the dielectric. Furthermore, by leveraging 3‐D printing to flexibly taper the complex longitudinal propagation constant, we also show that the same metallic parts can be reused for LWAs with completely different radiation pattern characteristics resulting in a practical LWA design approach with vastly lowered fabrication costs, lead time and design complexity. To validate this concept, we extract the longitudinal propagation constant from a modified transverse equivalent network model of the LWA and compare it against values obtained from full‐wave simulations. We then use these extracted values of the propagation constant to design, fabricate and experimentally characterise two one‐dimensional (1‐D) LWAs with an untapered and tapered amplitude distribution along the aperture to verify the proposed design concept.