An antenna-unit (110) for at least dual-FDD bands includes a first combiner (100) splitting its input (101) into at least two outputs (102, 103). Each output (102, 103) operates in at least two narrow-bands from two different FDD systems, and is respectively connected to a second and third combiners (200, 300). The second and third combiners (200, 300) are respectively connected with a first RF circuit (800, 900) enabling separation of two different FDD channels in an inverted Transmitter/Receiver fashion. An antenna system (700) based on the antenna unit (110) includes a set of columns of dual-polarized radiating elements (500) arranged on a reflector (702), and the first RF circuit (800,900) is connected with a second RF circuit (10) of the Base Station processing, SDR is set along with the RF circuit (10) to enable 3D beamforming features as well as independent system link control for optimization purpose.