High-Pass Sub-mmWave Filtering by Woven Textile Metamaterials

Textile metamaterials produced by a weaving of metallic and dielectric yarns are considered for filtering operations in the sub-millimeter band. A woven metamaterial was designed by parametric simulations aimed at producing a high-pass filter with a cutoff frequency at around 500 GHz above a high-reflective band and a strong rejection. The woven metamaterial is analyzed by means of an equivalent circuit formed by two resonant impedances, which are responsible of the rejection and high-pass features. A textile metamaterial was produced by an automatic weaving loom in a semi-industrial environment and it was electromagnetically characterized in free space. Experimental results are in good agreement compared with simulation and a phase-advance in transmission is evidenced. The phase of the reflection coefficient is also experimentally investigated thanks to a de-embedding process using a double-sided reflective mirror as a reference. Finally, the equivalent circuit of the fabricated textile is computed from the complex experimental reflection and transmission coefficients.