New Design of Beam-Formed Leaky-Wave Antenna Based on Substrate Integrated Waveguide in a Confined Space

A novel design of leaky-wave antenna (LWA) with beam-formed radiation pattern based on substrate integrated waveguide (SIW) is proposed in this communication. The design is based on the idea of superposing radiations from the $n = -1$ space harmonic of different periodic structures in a weighting way. The effect of structural parameters on the radiation performance is first studied using Fourier transform. Then, different periodic structures are mapped into a final composite structure to realize the desired radiation pattern, which is set to be a secant distribution according to the features of long straight confined space considered in this communication. Moreover, a novel double-layer SIW feeding network is proposed and used to construct an LWA array to improve the efficiency and gain. Simulated results are compared with experimental results to validate the proposed idea and design.