Flexible magnetic polymer composite substrate with ba1.5Sr1.5Z hexaferrite particles of vhf/low uhf patch antennas for uavs and medical implant devices

Our goal is to fabricate flexible magnetic polymer composites as antenna substrates for very high frequency (VHF)/low ultra high frequency (UHF) antennas for unmanned aerial vehicles (UAVs) and medical devices. Magnetodielectric materials, which have permeability (μ) similar to permittivity (ε), have attracted great attention, because they facilitate miniaturization of microwave devices while keeping or enhancing electromagnetic characteristics. Mechanically millled Ba_1.5Sr_1.5Co₂Fe₂₄O₄₁ (Ba_1.5Sr_1.5Z) hexaferrite particles were used to increase permeability in the interesting frequency band. The microwave properties of Ba_1.5Sr_1.5Z composites were predicted and measured. Hansen's zero-order analysis of antenna bandwidth and electromagnetic field simulation showed that the hexaferrite-based flexible composite could enhance a bandwidth and achieve the miniaturization of antennas as well. The magnetic antenna substrates can be a good solution to integrate antennas into the UAVs whose dimensions are comparable to or larger than communication wavelength.