On Synthesis of Orientation Insensitive Antennas

Internet of things (IoT) applications require orientation insensitive wireless devices to maintain stable and reliable communication as well as the positioning capability using the Global Positioning System. For those reasons, antennas providing near-isotropic radiation patterns along with wide far-field sphere polarization coverage, including linear and right-hand circular polarization, are highly demanded in IoT applications. In this paper, we present some theoretical limitations on the synthesis of an antenna with near-isotropic radiation and polarization patterns. We consider two models: a set of orthogonal Hertzian electric dipoles located at different points, as well as a model of Hertzian magnetic dipoles located on faces of a perfectly electric conducting cube. These models allow synthesizing the near-isotropic radiation and polarization patterns of an antenna based on short dipoles, as well as a cubic antenna with radiating patches on the cube faces.