All-Metal THz Leaky-Wave Antenna with Suppressed Open Stopband

A half-annular corrugated all-metal leaky-wave antenna is designed based on asymmetric unit cells. The adoption of two non-identical perturbations of the metallic profile (i.e., of the groove) for each unit cell is applied to demonstrate the capability of suppressing the open stopband and thus improving the radiative performance when scanning through broadside. The use of trapezoidal grooves, which provide an asymmetric perturbation with respect to the propagation direction of the guided mode, is also considered for the same purpose. An in-house method-of-moments code is implemented and optimized to study the dispersion behavior of the relevant leaky modes, whereas the radiative performance is analyzed by full-wave simulations to validate the scanning behavior of the proposed antenna. The results show that, thanks to the one-sided configuration and a quasi-flat nonzero attenuation constant, a linear scanning behavior and almost constant gain through broadside can be achieved at terahertz frequencies with all-metal compact structures.