Characterization of a Pentagonal CSRR Bandpass Filter for Terahertz Applications

With the fast magnification of terahertz (THz) technology, it becomes necessary to regulate the terahertz wave transmittance resourcefully. THz filters are crucial for managing devices in THz communication. A metamaterial-based THz bandpass filter (BPF) using a complementary split-ring resonator (CSRR) is proposed with the structure of a square in pentagon (SP). The proposed filter provides high tunability over resonant frequency and bandwidth. The result shows that the resonant frequency of the designed filter is 7 THz, a maximum 3 dB bandwidth of 1.6 THz, return loss of − 28.66 dB, low insertion loss of − 0.001 dB, and the transmittance is almost 100%. The proposed THz filters are used in security screening and biomedical imaging.