Stacked antenna structure for radiation of orthogonally polarized signals

Abstract From the Canadian patent

A resonant circularly or elliptically polarized microstrip radiator wherein the size of the radiator is reduced in the resonant or non-resonant dimensions or both, without reducing the effective resonant dimension or substantially lowering the efficiency of the radiator. Reduction of the resonant dimension is provided by folding the resonant cavity, while reduction of the non-resonant dimension is facilitated by utilization of a low density low loss dielectric, such that the loss resistance of the element is appreciable with respect to the radiation resistance of the element. The preferred embodiment comprises interdigitated antenna structures.