Circular polarization is a key electromagnetic property for applications like wireless communication, sensing technologies, radar systems, and detection platforms. Dynamic control over polarization states and radiation patterns is crucial for enhancing performance. Spin-momentum locking (SML), a phenomenon in evanescent waves, plays a vital role in achieving circular polarization. SML involves the strong coupling between a wave’s propagation direction, spatial decay, and the spin of the electric field, forming a right-handed triplet. This relationship allows precise manipulation of circularly polarized radiation, minimizing the impact of material losses or complex designs. This study demonstrates that leveraging SML enables highly efficient circularly polarized radiation over a broad frequency range with a simple structural design. Simulations show high polarization purity and dynamic control over polarization and radiation direction, making the design adaptable and cost-effective for various applications in communication and sensing systems.