Low-profile helical-like antenna for radiating circular polarization parallel to ground plane

Abstract

This letter is devoted to a circularly polarized (CP) low-profile antenna radiating parallel to its ground plane. The proposed antenna has a capacitive feeding structure resulting in a small dimension of 0.127λ₀ × 0.059λ₀ and the short height of 0.01λ₀ at 1.77 GHz, where λ₀ is the wavelength at the resonant frequency. Even though the structure is low-profile, the radiation efficiency can reach at 70% (Simulated) with a small gap. The proposed antenna can radiate LHCP (Left-hand CP) and RHCP (Right-hand CP) in the opposite directions parallel to the ground plane.