A Band-Stop Plasmonic Filter Based on Spoof Surface Plasmon Polaritons

In this paper, a band-stop plasmonic filter based on the spoof surface plasmon polaritons is proposed, which can achieve high-efficiency band rejections and tunable bandwidth and frequency by etching periodic grooves on the middle line of coplanar waveguide (CPW). Measured results shown the reflection coefficient is -2 dB, and the transmission coefficient is less than -30 dB in the stopband. The operating principle is explained by using the dispersion curves and electric field distributions. The good agreements between the simulated and measured results validate the proposed design. The easy fabrication and good band-stop features make the proposed filter potentially useful in the integrated microwave circuit and device.