A dual-polarized SIW lens antenna array for Rx-/Tx-integration at K/Ka-band
The terminal antenna with dual circular polarization reported here operates around 20GHz and 30GHz, i.e., in the down- and uplink frequency bands of current satellite communication systems. The passive array, this work focuses on, integrates the receive and the transmit paths (Rx/Tx) in a single aperture. This approach is shown to be advantageous compared to classical solutions with two separate antennas. The modules, the array consists of, are formed by a stack of eight linear sub-arrays which themselves are composed of an alternating series of four Tx-only and four combined Rx/Tx end-fire antenna elements. The resulting brick architecture provides enough real estate for the future implementation of phased array electronics. The array is implemented in substrate integrated waveguide (SIW) technology. For improved matching, it is covered with a periodically shaped dielectric lens. A technique is proposed to mitigate cross-polarization in the pointing direction. A module is realized using standard technologies. The relevant array parameters are measured. The module patterns are synthesized from the individual element responses. They confirm the simulated results and, in particular, a bandwidth of more than 2.5GHz for both Rx and Tx.