Shared Aperture K- and Ka-Band Antenna Array for Satellite Communications

The design of a shared aperture dual-band and dualpolarized antenna array is presented for the K- and Ka-band satellite communications. The antenna operating at either band shares similar geometries, consisting of four small square patches fed by two orthogonally deployed inverted-F shaped antennas (IFAs) and an L-shaped metal strip to enhance inter-port isolation. By optimizing the geometrical sizes, two types of antenna elements are adjusted to operate in the K- and Ka-band, respectively. A novel topology for intersectional arranging of low-band and highband antenna elements is proposed, using a nested configuration of triangular and rectangular layouts. The proposed antenna array, verified through simulations, can generate dual orthogonal linearly polarized waves over 18.6-21.1 GHz and 25.5-32.5 GHz, with inter-band isolations better than 17 dB and 15 dB, respectively. The typical realized gain is 13.2 dBi at 19 GHz and 16.2 dBi at 29 GHz, respectively.