A Flexible Low-Pass Filter Based on CPW-SSPPs

This paper proposes a flexible low-pass filter structured with only a single metal layer of CPW-SSPPs on a polyimide film substrate. Spoof surface plasmon polaritons are realized by carving periodic rectangular grooves on both sides of the CPW ground. The flexible low-pass filters in two states, flat and bent, are designed and simulated. The simulation results show that the designed flexible CPW-SSPPs low-pass filter have very sharp transition band and good stopband performance. The proposed flexible low-pass filter has a very low insertion loss of less than 1.93 dB under 5.2 GHz in the unbending state, and the out-of-band rejection is higher than 30 dB in the frequency range of 5.82–12 GHz, and compared with the flat state, the change of the S-parameters is very small in the bending state, and the designed flexible CPW-SSPPs low-pass filter can be applied in the bending state.