Dual-band circularly polarised antenna with hemispherical coverage

摘要

A circularly polarised antenna including first and second multiple patch antenna structures dimensioned to operate at two distinct frequencies, each antenna structure consisting of four shorted patches, the patches (11a) of the first structure being spaced from a ground plane (10) by dielectric material (12), the patches (14a) of the second structure being spaced from the patches of the first structure by dielectric material (13), the patches of the second structure each overlying a corresponding patch of the first structure and each having a dimension λ_m⁽²⁾/4 which is less than the dimension λ_m⁽¹⁾/4 of the corresponding patch of the first structure, with feed means (16a, 17a) for each of the patches, the patches of both structures being disposed in the planes of the patches so that the radiating edges of the two patch structures form superimposed antenna structures.