In this work we present a complete transmitarray antenna system (aperture and feed) for SoTM ground terminals at Ka-band. The feeding structure is composed by several modules: a compact (10.9 x 10.9 x 18.0 mm) dual-port dual-band linearly polarized waveguide antenna; a dual band polarizer that provides circular polarization with orthogonal sense between Rx/Tx bands and polarization switching; a dielectric lens that increases the antenna directivity for a proper TA illumination and at the same time shifts the feed phase center. This virtual focus approach allows to reduce the overall TA antenna height. The development prototype provides mechanical scanning up 50º degrees in the elevation plane with 23 dBi and 25 dBi in the Rx and Tx respectively, occupying a 195 x 145 x 100 mm3 volume.