This ultra-lightweight right-hand circularly polarized (RHCP) or left-hand circularly polarized (LHCP) antenna is designed for airborne, UAV, and missile data-link applications. It operates over a wide frequency range of 2–18 GHz, providing a gain of ≥0 dBic at 2 GHz, ≥8 dBic at 8 GHz, and ≥5 dBic at 18 GHz. The antenna has a maximum axial ratio of 3.5 dB, with an E-plane and H-plane beamwidth ranging from 110° to 40°. It features a 50-ohm impedance, a typical VSWR of 2:1 and a maximum VSWR of 3:1, and is equipped with an SMA female connector.