Artificial surfaces with interwoven and tessellated patterned conductors: Properties and phenomenology

The features of artificial surfaces composed of doubly periodic patterns of interwoven planar conductors are discussed. The free-standing intertwined quadrifilar spirals and modified Brigid´s crosses are presented as illustrative examples to demonstrate the highly stable angular reflection and transmittance response with low cross-polarisation and a broad fractional bandwidth. The main mechanisms contributing to the substantially sub-wavelength response of these arrays are discussed showing that interweaving their conductor patterns provides concurrent control of both the equivalent capacitance and inductance of the unit cell. The effects of dielectric substrate and conductor thickness on the properties of intertwined spiral and modified Brigid´s cross arrays are discussed to provide insight in the effect of the structure parameters on array performance.