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A C‐/Ka‐band circularly polarized (CP) shared‐aperture scanning antenna array has been proposed in this paper. Here, the antenna array working in the C‐band (6.48–6.52 GHz) is composed of 4 × 4 cross‐dipole antenna elements, and each cross‐dipole antenna element is fed by a 1‐to‐2 power divider with 90° phase difference, so that it can induce left/right‐hand CP wave. As for the antenna array working in the Ka‐band (27.5–28.5 GHz), it is made up of 16 × 16 CP antenna elements, in which each CP antenna element is an aperture‐coupled chamfered patch fed by substrate integrated waveguide (SIW) structure. To realize the proposed scanning array, the C‐band antenna array is set within the gap between adjacent antenna elements of the Ka‐band antenna array, and the radiation apertures of all the antenna elements are printed on the same plane. Notably, such a layout can yield good isolation performance between the C‐band antenna and the Ka‐band antenna element. From the measured results, in the C‐band, the proposed scanning array can achieve a beam scanning range of 0°–38° with axial ratio (AR) < 3 dB, a port isolation of greater than 45 dB, and a maximum gain of 18.2 dBic. On the other hand, in the Ka‐band, the proposed scanning array can yield a beam scanning range of 0°–45° with AR <3 dB, a port isolation of greater than 37 dB, and a maximum gain of 26.2 dB. [ABSTRACT FROM AUTHOR]

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.

Introduction. Introduction. Low-profile effective antenna systems (AS) with maintained directional characteristics in a wide sector of scanning angles are required for satellite communication at mobile objects. This article investigates the directional characteristics of a subarray based on a Fabry–Perot cavity and an antenna array with mechanoelectrical beam steering.Aim. To investigate a Fabry–Perot based antenna array with mechanoelectrical beam steering and to estimate its gain and directivity at different scanning angles.Materials and methods. Computer simulations were carried out using the finite element method (FEM), finite difference time domain (FDTD) method and template based post-processing.Results. A subarray based on a Fabry–Perot cavity for an antenna array with mechanoelectrical beam steering was simulated. The efficiency of the subarray comprised at least 65 % in the 11.9…12.5 GHz frequency band. An antenna array based on a Fabry–Perot cavity with mechanoelectrical beam steering was developed and investigated. The calculated characteristics of the developed antenna array agreed well with those obtained experimentally. The gain degradation did not exceed 2.5 dB in the 0…70° scanning angle range. The advantages of using antenna elements based on a Fabry–Perot cavity and developing on their basis mobile satellite antenna systems with wide-angle scanning are noted.Conclusion. The use of a radiator based on a Fabry–Perot cavity and the development on it basis an antenna array with mechanoelectrical beam steering provides an antenna efficiency of no less than 0.5 with a gain degradation of no more than 2.5 dB in the scanning angle range 0…70° from 11.9 to 12.5 GHz.