A compact ultra‐wide‐beam quasi‐coaxial‐structure fed crossed‐dipole.

A compact ultra‐wide‐beam crossed‐dipole antenna for K‐band phased arrays is proposed. The superior wide beamwidth is achieved by loading four vertical parasitic structures around the dipole patches. A quasi‐coaxial feeding structure is proposed as the antenna size is limited in K‐band, and it cannot be coaxially fed by the conventional feeding method. This structure is constructed by using PCB through‐plated vias, achieving a compact design. The antenna has a compact size of 0.37λ × 0.37λ × 0.35λ (λ is the free space wavelength). The simulated and measured results show that a half‐power beamwidth of more than 140° (from −71° to 72°) and an axial ratio beamwidth of 100° (from −51° to 49°) can be realized. [ABSTRACT FROM AUTHOR]