Water and Oil Emulsion Antennas for Compact Low Frequency Applications

Water-in-Oil (W/O) and Oil-in-Water (O/W) emulsions may be used to economically manufacture high permittivity compact dielectric resonator antennas. Compact antennas for low-frequency applications allow for the efficient deployment of massive Multiple Input Multiple Output (MIMO) solutions within the sub-GHz bands as well as elevated levels of power transfer in Microwave Power Transfer (MPT) applications. In order to achieve such miniaturization, Dielectric Resonator Antennas (DRAs) may be used alongside high permittivity materials. Nonetheless, such materials require complex manufacturing, elevated costs and allow for discrete permittivity selection. Emulsions permit for the selection of an arbitrary value of permittivity, continuously ranging between those of the components at furthest extremes. In this work, the dielectric properties of W/O and O/W emulsions are characterized and modeled in order to simulate a miniaturized DRA optimized for operation at sub-GHz frequencies. The simulation demonstrates the validity of such emulsions as substitutes for state of the art high permittivity dielectrics at low frequencies, when arbitrary permittivity selection, low-cost and/or simplicity of manufacturing are required.