Fully-Metallic 3-D Cells for Wideband Applications

This communication presents a novel full-metal 3-D periodic structure that allows for the excitation of phase resonance. This phenomenon, thanks to the 3-D geometry, enables the individual control of the phase response of each polarization along the frequency band. This structure is inspired by square waveguides that have open resonators slotted on the walls. An extended study has been carried out by modeling the unit cell via equivalent circuits with the goal of developing a powerful optimization tool instead of using more resource-consuming software. An ultrawideband electric-field rotator covering a bandwidth of 141.8% has been designed with the aid of the circuit model (CM) and has been manufactured via 3-D-printing laser powder bed fusion (LPBF). The experimental results have been validated with success.