Properties of circularly polarised spherical retrodirective array

In this paper we provide the first ever discussion of the characteristics of a spherical retrodirective array. The array is populated with planar circularly polarised (CP) microstrip patch antennas. The proposed retrodirective array offers significant potential to realise orientation-agnostic, continuous, self-steering coverage in both hemispheres. In this work we use numerical full-wave simulations to determine for the first time the main radiation characteristics, far-field and axial ratio, of a spherical CP retrodirective array operating at 2.45 GHz and describe their dependence on both orientation and aperture cross section. Beampatterns with main lobe directivity of 16−16.6 dBi, comparable indirectivity to a planar array of the same aperture, that preservethe handedness of the pilot signal, are presente in all cardinal directions