Programmable bandstop filter based on spoof surface plasmon polaritons

Spoof surface plasmon polaritons (SSPPs) have been developed rapidly because of the advantages of strong field constraints, low inter-channel cross talk, and low loss. However, the functions of plasmonic devices made of traditional passive SSPPs are completely fixed and cannot reach reconfigurable capability once the devices are fabricated. For the current development status, it is an urgent issue to design a reconfigurable device to control SPP waves dynamically in real time. This paper proposes a dynamic reconfigurable bandstop filter by using the concept of programmable SSPPs. The filter has a significant regulation function in the wideband range from 4 GHz to 22 GHz. The center frequency, number, and bandwidth of the stop band can be reconstructed in real time by programming the bias voltage, and the transmission coefficient (S21) has good transmission performance of more than -3dB. The results show that the experimental processing test is close to the theoretical simulation results, which proves the feasibility of the designed device. The study extends the functional principles of information science and digital logic to the application of physical devices.