Abstract
A novel dual-band conformal surface plasmons (CSPs) waveguide is designed and well studied in this paper. In earlier researches, we have recognized that electromagnetic field of CSPs waveguide are always confined to a sub-wavelength area and have a strong potential to be applied in devices designing. However, almost all of the earlier CSP structures is mainly focus on the fundamental mode characteristics with only single resonance frequency. Here we propose a innovative dual inverted-L structure with excellent performance not only on the fundamental mode but also on a new upper mode. This structure operates in microwave frequencies regime and shows outstanding frequency tunability characteristic. Being different from frequency characteristics in the earlier CSP waveguides which always used to be designed single-frequency device, dual-frequency tunability can be obtained via the dual L-type bending branch of the periodical CSP structure. In present paper, we also realize a tunable dual-frequency filter by changing the scaling factor of inverted-L stubs.