Broadband planar achromatic anomalous reflector based on dispersion engineering of spoof surface plasmon polariton

Planar reflectors are generally composed of non-uniform inclusions positioned on conducting sheet. Restricted by strong dispersion of the inclusions, the reflection of planar reflectors is usually chromatic. In this letter, we first obtain the dispersion relation for planar achromatic anomalous reflector (PAAR). Then, we propose to realize the dispersion relation based on dispersion engineering of spoof surface plasmon polariton (SSPP). Metallic blades structure is proposed to achieve the linear dispersion response by tailoring the weak dispersion region of SSPP. 6 metallic blade structures are designed to compose the super cell of the PAAR. A prototype was fabricated and measured. Both the simulation and experiment results show that the PAAR can achieve an achromatic reflected angle of 49.3° in 10.7–11.7 GHz under normal incidence.