A two-dimensional beam scanning continuous transverse stub antenna based on a single-layer compact linear source generator

To minimise the profile of Satcom-on-the-Move ground terminals, in this study, a two-dimensional beam-scanning continuous transverse stub antenna that is based on a compact linear source generator (LSG) is presented. A periodic anti-symmetric two-step (ASTS) structure cascaded with a broadband network is used to construct a single-layer compact LSG. The concept of a parallel-plate waveguide polarisation twister is used to design the ASTS unit that acts as a TE₁₀-to-transverse electromagnetic wave converter, to which chamfers and T-type grooves are added to improve the output plane wave performance over the entire frequency band. A prototype array operating in the band 10.95–12.75 GHz is designed, fabricated, and measured, and the experimental results agree well with the simulated ones. A beam-scanning range of ±61° in elevation is achieved at the central frequency. Although only 29 of 36 slots (ϕ = 0°) contribute to the radiation, the antenna aperture efficiency is still over 60% due to the superior performance of the single-layer minimised LSG.