A Metal-Only Holographic Leaky-Wave Antenna Based on Spoof Surface Plasmon Polaritons

This paper presents a metal-only sinusoidal modulated metasurface (MTS) leaky-wave antenna (LWA) with an operating frequency of 18 GHz. Avoiding dielectric losses at high frequencies and withstanding harsh environmental conditions in space exploration are the advantages of metal-only antennas. In spoof surface plasmon polariton (SSPP) structures, the electromagnetic wave of the dominant TM mode is confined at the boundary of two environments. By utilizing the holographic technique and development of pseudo-periodicity in the SSPP structures and consequently stimulating the Floquet mode harmonics, the dispersion curve of the SSPP mode is located inside the radiation cone, and the leakage and radiation conditions of surface wave are provided. The proposed LWA is composed of cross-shaped unit-cells. The realized gain and efficiency of the LWA are 26.5 dBi and 86%, respectively.