The present invention relates to a method for beamforming a beam using an active antenna having predetermined aperture data predetermined aperture data comprising M×N dual polarized antenna subarrays within an aperture, each dual polarized antenna subarray comprising a first antenna subarray having a first polarization and a second antenna subarray having a second polarization non-parallel with the first polarization. The method comprises: selecting number of antenna ports, each antenna port being adapted to generate a separate beam using a combination from the first antenna subarray and/or the second antenna subarray; selecting port properties, comprising target beamwidth for each separate beam and desired polarization between beams; and determining port partitioning based upon aperture data and port properties for each antenna port, to adjust an effective length of the aperture over which the beam is created and thereby defining which first antenna subarray(s) and/or second antenna subarray(s) to use for each antenna port.