A X-/Ka-Band Linearly Polarized Low Profile Shared-Aperture Antenna Array for Satellite Applications

An $X- / Ka$ -band shared aperture scanning antenna array for satellite applications is proposed. The Ka-band antenna array consists of 8 $\times $ 8 antenna elements in a triangular grid, while the X-band antenna array consists of $4\times $ 4 antenna elements in a rectangular grid. Notably, the antenna elements of Ka band array and X-band array are planar microstrip dipole antennas to avoid structural overlap and reduce mutual coupling. Besides, the $X$ -band antenna elements and $Ka$ -band antenna elements are interlaced to share the same aperture. Compared with the recently released dual band shared aperture antenna array, the profile of the proposed antenna array is only 0.05 times the air wavelength. The frequency ratio ( $f_{high} / f_{low}$ ) of the proposed antenna array is 3.1, and the antenna number ratio ( $N_{Ka} / N_{X}$ ) of the antenna array is 4. These two parameters are close, which can improve the aperture utilization of the array. The measurement results show that the scanning angles of the antenna array at 10GHz and 30GHz are 38° and 30°, respectively.