A THz Spoof Surface Plasmon Polariton Band Pass Filter for 6G Communication Applications

This paper presents a proof-of-concept terahertz (THz) spoof surface plasmon polariton (SSPP) bandpass filter operating at sub-THz frequencies (near 300 GHz band) for 6G communication applications. The filter operates by integrating a transition circuit and SSPP waveguide into a coplanar strip feedline. The passband insertion loss at 260 GHz is 6.8 dB considering the conductor and substrate losses. The out-of-band rejection is more than 20 dB for low frequencies and more than 30 dB for high frequencies. The filter demonstrates a 3 dB bandwidth of around 90 GHz, covering the frequency range from 230 to 320 GHz.