I. Introduction
The current state of the art in the development of submillimeter, millimeter, and microwave electromagnetic (EM) materials is determined, in many respects, by the success in the design, fabrication, and tailoring of artificial composite materials. Such materials, constituted by variously shaped electrically small inclusions embedded in a host medium, can often exhibit pronouncedly properties (chirality, anisotropy, and nonlinearity) unattainable on such a high level in natural media. Conductive polymer composites find large-scale applications as antistatic materials, in printed electronics, supercapacitors, organic solar cells, biosensors, flexible transparent displays, etc. [1]. In spite of the practical limitations of use because of their confined processability and manufacturing cost, dc and ac conductive composites are rapidly gaining attention in new applications such as packaging for electronics and chemical industry, metal replacement, heating elements and fuel cells, and for EM shielding and absorption in gigahertz and terahertz frequency ranges, where traditional radar materials [2], if not completely inapplicable, lose their attractiveness due to rising consumer wants.