Upon Delegation Request (*) The objective of the activity is to develop and validate a mobile terminal antenna that supports satellite connectivity and terrestrial 5G. A prototype of the antenna will be manufactured and tested in a laboratory environment. Targeted Improvements: Terminal size, weight and power reduction (30 to 50%) achieved by integrating 5G satellite and terrestrial antenna systems.The integration of satellite communications into 5G terrestrial networks is desirable to benefit from the global coverage provided by satellites and offer access to a much larger market to satcom operators. This provides an opportunity for the development of universal mobile terminals providing connectivity to both the satellite and terrestrial networks sharing the same antenna aperture or enclosure. For example, integrated medium/large ground mobile terminals (e.g. trains, busses, etc.) can be designed to provide broadband connectivity by the 5G terrestrial network in urban environment and by the satellite network in rural areas, thus achieving seamless continuity of service.To support this use case, this activity is aimed at the development of a combined antenna providing 5G terrestrial and satellite connectivity for land mobile terminals based on flat panel antennas that reduces the SWaP (Size, Weight and Power) with respect to two independent apertures. The antenna will provide beam steering for the satellite connection anddual-beam operation to allow continuity of service when switching from a network to the other (i.e. make-before-break handover approach). Wideband or dual-band operation will be required to combine the standard satellite frequencies (Ku or Ka band) and the terrestrial frequencies in the same radiating aperture or enclosure. For the 5G terrestrial connection, the most convenient frequencies are to be chosen by the bidder among the several available 5G bandwidths. The activity will define different scenarios that will be the basis for the antenna requirements. The activity will then identify and trade off different technical options that will be down selected to the most promising one. Finally, a prototype will be developed, manufactured and tested in a laboratory environment to validate and demonstrate its performance. (*) Upon Delegation Request activities will only be initiated on the explicit request of atleast one delegation.