Shared-aperture dual-band spoof surface plasmon polariton leaky-wave radiator

In this paper, a shared-aperture dual-band leaky-wave radiator based on spoof surface plasmon polaritons (SSPPs) and substrate-integrated waveguide (SIW) is presented. The SSPP structure, consisting of the periodic parasitic stubs, acts as a periodic leaky-wave antenna (PLWA) operating in the lower frequency band, while the central conductor of SSPP plays the role of an SIW-based leaky-wave antenna (LWA) suitable for higher frequency operation. Transverse slots are etched on the top metal layer of SIW. As a result, two kinds of LWAs are designed within a single shared aperture operating in dual bands, and the frequency ratio of the two antennas can be changed flexibly. Besides, this presented LWA realizes horizontal-polarization (H-pol) in both frequency bands due to exciting the even mode of SSPP and utilizing a quasi-uniform SIW leaky-wave antenna. Measured results of the fabricated prototype exhibit that this antenna operates from 6.0 to 11.0 GHz within the lower frequency band and from 22.5 to 23.5 GHz in the higher frequency band. Both the radiation patterns in dual bands show the beam-scanning property.