SIW-Based Composite Right/Left-Handed Metamaterial for Ku-K Band Frequency Scanning Antennas

This work presents a planar CRLH SIW metamaterial unit cell for Ku-K band antenna applications, enabling frequency scanning-based beam steering. Interdigital slots on the SIW surface create alternating left-handed (backward) and right-handed (forward) passbands. The CRLH band spans 15.79–22.92 GHz with a transition at 17.91 GHz, operating in the radiating region above 15.79 GHz. The dispersion characteristics of the proposed unit cell exhibit frequency-scanning from backfire to end-fire, including broadside operation, making it well-suited for high-frequency leaky-wave antenna systems in advanced communication applications.