The substrate (1) is transparent in one of infrared and visible spectral range, and is penetrated by continuous channels (2). The metallic coated antenna elements e.g. nantotubes (3) are provided in the continuous channels. The antenna elements are equally spaced from one another in longitudinal direction of the channels. The gap (4) between nantotubes and channels is not greater than 10 Nm. The internal diameter (d) of the nantotubes is less than 150 Nm. The channels are made to extend parallel to one another in the substrate which is made of anodized metal oxide or porous silicon.