Design and simulation of terahertz mesh bandpass filter

A fourstage cascade terahertz mesh bandpass filter has been designed according to the atmospheric absorption windows of terahertz waves. The center frequency of the filter is 0.25 THz, the bandwidth is 0.1 THz at 3 dB, the transmittance is greater than 80%, the ripple factor is less than 0.5 dB in the passband, and both of the center frequency and the bandwidth can be adjusted by scaling the size of mesh slot. The HFSS simulation conducted under periodic boundary conditions and absorbing boundary condition of perfectly matched layers shows the transmittance and insertion loss of this filter with different mesh arrangements anddielectric substrates, under incident waves of different incidence angles and different polarizations.