The copper-cladded Rogers RT/DuroidTM 5880 substrate with a relative dielectric constant of 2.2 and a height of Hsub = 0.254 mm was selected. The TC-UAJC element was etched on the 17 μm thick copper sheet on its upper surface. The HFSS solution frequency was selected to be 20 GHz for a (0.5–20) GHz frequency sweep. The maximum scan volume was θ = 70°. To minimize the simulation time and the amount of discretization, the metals in the HFSS model were taken to be perfect electric conductors (PECs). The zeroth-order Floquet modes, TM00 and TE00, were used for scanning in the y-z and x-z planes respectively as shown in Fig. 2. The electric field of the TM00 Floquet mode is parallel to the plane of incidence (along the y-direction) and the electric field of the TE00 Floquet mode is perpendicular to the plane of incidence (along the x-direction).Figure 2Top view of the unit cell. (a) The TM00 floquet mode fields. (b) The TE00 Floquet mode fields at the face of the top Floquet port.