A Low-Profile Wideband Wide-Scan Tightly Coupled Dipole Array for X-Band

In this paper, a low-profile wideband wide-scan tightly coupled dipole array (TCDA) for X-band is designed. The antenna based on tightly coupled dipole elements. A thin wide-angle impedance matching (WAIM) layer over the array aperture is used to achieve broadband and wide-angle scanning. The antenna is excited by a coaxial line with 50Ω characteristic impedance. Simulated results show that the design can achieve a 1.5:1 (from 8 GHz to 12 GHz) bandwidth while scanning to ±60° in both the E-plane and the H-plane, subject to VSWR < 2.5. The antenna unit has a very low profile (0.23λ, λ is the minimum free-space wavelength in the operating band) and large size (0.52λ). The overall structure of the antenna is composed of multi-layers dielectric substrate, which has good reliability and stability. It can works in environments with large vibrations, such as airplane wings. It is suitable for airborne fire-control radar system.