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Abstract-An electrically small wire cage antenna is presented as an alternative to previously proposed spherical split-ring (SSR) antennas, which achieve Q's near the lower limit defined by Chu. This design is targeted to approach the same lower bound, but constructed in a manner more economical for production. The proposed dual-polarized wire cage structure is produced using a standard dielectric substrate which is patterned front and back with copper, using well-defined and reproducible etching procedures. The thin interdigitated structure is then placed over a ground plane using rigid conducting elements that help to suspend the dielectric substrate while completing the wire cage. A parameterized HFSS model was used to optimize performance. Measurements were made on fabricated prototypes that demonstrate performance consistent with simulated results, confirming that SSR antennas and their derivatives are capable of approaching Chu's limit on the radiation efficiency of electrically small antennas.Index Terms-Chu limit, electrically small antenna, magnetic dipole antenna, spherical split ring, wire cage antenna.