Broadband circularly polarized cavity-backed antenna

The design and experimental investigation of a circularly polarized antenna with circular slot for broadband characteristics is proposed. The horizontal and vertical probes of the L-shaped probe, which is a key element to generate circular polarization, are separated in the structure, contrary to the concept of having joined probes. Another novelty of placing stubs in the slot, which are attached to the ground plane, is proposed to improve the axial ratio (AR) characteristics of the antenna by around 10%. Unidirectional patterns can be obtained by having a cavity of height I_g/4 behind the antenna and is effective when no stubs are placed in the slot.