This work deals with an Rx/Tx integrated array antenna for mobile satellite communications at K/Ka-band. The realization is enabled by substrate integrated waveguide (SIW) technology, which is studied in-depth. A transmission line model for so-called multilayer substrate integrated waveguides is developed. It takes losses and conductors with rough surfaces into account. Based on the model, components are designed and, finally, assembled to realize a passive dual-polarized array antenna. This demonstrates that a significant size reduction is possible compared to separate antennas for Rx and Tx.
