A Daul-Band Shared-Aperture Antenna Array

In this paper, a compact wideband wide-scan dual-band shared-aperture antenna (SAA) is designed. In order to reduce occupied space, the X-band antenna with horizontal polarization and the S&C-band antenna with vertical polarization are arranged in a staggered manner on the same aperture. The S&C-band element is a tightly coupled dipole, printed on vertical substrate backed with ground plane. The structure of X-Band element is open-ended rectangular waveguide radiator, feeding with coaxial probe. A three-step ridge waveguide is used to improve the impedance matching and increase the bandwidth. The antenna can operate in S&C-band (from 2 to 6GHz) and X band (from 8 to 11GHz), while scanning up to ±30° in the AZ-plane and EL-plane, subject to VSWR < 3.