Printed dipole antennas on substrates reinforced with unidirectional conducting fiber

Fiber reinforced composites offer strength and light weight but are electrically anisotropic. The resonant frequency of dipole antennas is orientation dependent. While FEM modeling showed a cosine relationship between the effective permittivity and angle, experimental measurements at UHF on cardboard reinforced with fine copper wire did not fit this relationship. The electromagnetic anisotropy has implications for radio communications systems located on UAVs and other platforms. Carbon nanotubes in polymeric composites provide a renewable option for high strength materials.