This paper proposes a novel terahertz metamaterial modulator utilizing vanadium dioxide phase-change materials, which adopts three nested square split rings as a unit cell. The modulator can achieve dual functions of band-stop filter and bandpass filter by vanadium dioxide filled in the gap of split ring changing phase. The simulation results show that the central frequency of the modulator is around 0.83 THz, whether the modulator is at band-stop state or band-pass state. The modulator shows that the -3 dB bandwidth reaches to 30 GHz at the state of band-pass, and that the -20 dB bandwidth reaches to 160 GHz at the state of band-stop.
In this paper, a novel terahertz modulator using the phase transition characteristics of vanadium dioxide to achieve both band-pass and band-stop filter states is proposed. The regular hexagonal split-ring is used as a unit structure, and the center frequency can be changed by changing the size of the regular hexagon. The simulation results show that any frequency between 0.1~1THz can be used as its center frequency. In the case of 140 um regular hexagon cell, the band-pass filter state shows that the -3dB bandwidth reaches to 100 GHz, and the band-stop filter state shows that the -20dB bandwidth reaches to 75 GHz. Furthermore, a mirror-type regular hexagonal structure is designed as unit cell, which can improve the modulator performance in both states.