Study of Spoof Plasmon Formed on Periodically Corrugated Metal Surface Based on Cavity Resonance Method

We experimentally studied spoof plasmons developed on a metal cylinder with rectangular corrugations. Cavity resonance method using vector network analyzer is employed to examine electromagnetic properties of the spoof plasmon. The dispersion characteristics are obtained using resonance frequencies and can be recognized as two regions: bounded and hybrid surface-wave regions. The bounded surface wave is formed near the upper cutoff frequency, while the hybrid surface wave similar to a Sommerfeld wave is formed away from the upper cutoff frequency. In addition to the dispersion characteristics, the reflectance of spoof plasmon at the corrugation end is examined, based on quality factors of resonant modes.