A S/C Dual-Band Dual-Polarized Shared Aperture Antenna Array for Retrodirective Arrays

A S/C dual-band dual-polarized wide-scan shared-aperture antenna array for retrodirective arrays is proposed in this paper. Both arrays have a rectangular lattice with the element spacing proportional to the operating frequencies at 3.8 GHz and 5.8 GHz, which meets the configuration requirements of arrays in retrodirective systems with different operating frequencies. Two arrays share the same aperture through height differences of dipole antennas printed on a single layer of substrate. Elements in two arrays are placed perpendicular to each other, exhibiting orthogonal polarizations. Improved isolation between the two bands is accomplished through the filters on the feed lines. Simulated results demonstrate that the proposed array exhibits good impedance match with a relative bandwidth nearly 31%. Optimized parasitic patches enable scanning capabilities of the array up to $\pm \mathbf{60}^{\circ}$ at two main operating frequencies.