Fig. 1. Schematic diagram of metamaterial filter cell structure. (a) Three-dimensional schematic diagram; (b) side view; (c) schematic diagram of metal layer structure

Fig. 2. Effect of metal line width w on filtering performance. (a) Filter transmission spectra at different line widths w; (b) plot of line width w and center frequency of first resistance band versus bandwidth

Fig. 3. Effect of spacing m on filtering performance. (a) Filter transmission spectra at different intervals m; (b) plot of interval m and center frequency of first resistance band versus bandwidth

Fig. 4. Effect of outer radius R₁ on filtering performance. (a) Transmission spectra of filters with different outer radii R₁; (b) plot of outer radius R₁ and center frequency of first resistance band versus bandwidth

Fig. 5. Transmission spectra of metamaterial THz band resistance filter

Fig. 6. Electric field distributions of three resonance points. (a) Electric field distribution of frequency f₁=0.414 THz; (b) electric field distribution of frequency f₂=0.518 THz; (c) electric field distribution of frequency f₃=0.892 THz

Fig. 7. Surface current distributions of three resonance points. (a) Current distribution of frequency f₁=0.414 THz; (b) current distribution of frequency f₂=0.518 THz; (c) current distribution of frequency f₃=0.892 THz

Fig. 8. Specific process of micro-nano lithography

Fig. 9. Filter object and metal resonance unit. (a) Filter sample physical drawing; (b) structure of metal resonance unit under electron microscope

Fig. 10. Test spectrum map of THz band resistance filter sample