A waveguide device for a dual-polarized antenna array, the waveguide device comprising: a plurality of antenna elements distributed in an array of columns and rows in first and second dimensions, each antenna element having a waveguide propagation direction along a third dimension, wherein each antenna element comprises a common waveguide and a septum polarizer having a longitudinal axis extending in the third dimension and arranged to divide the common waveguide into a first waveguide (215a; 315a) associated with a first polarization and a second waveguide (215b; 315b) associated with a second polarization, wherein each of a first set of the septum polarizers (210-a) has the same orientation and is inverted by rotation by 180 degrees around the longitudinal axis of the septum polarizer relative to each of a second set of the septum polarizers (210-a) to form first groups of four adjacent first waveguides of the first waveguides arranged as two rows and two columns, and to form second groups of four adjacent second waveguides of the second waveguides arranged as two rows and two columns; and a waveguide feed network comprising: a first waveguide feed stage comprising a first plurality of waveguide combiner/dividers coupled between the four adjacent first waveguides of the first groups and first intermediate waveguides and a second plurality of waveguide combiner/dividers coupled between the four adjacent second waveguides of the second groups and second intermediate waveguides, wherein the first waveguide feed stage has a waveguide propagation direction that is substantially aligned with the third dimension; and a second waveguide feed stage coupled with the first intermediate waveguides and the second intermediate waveguides, wherein the second waveguide feed stage has a waveguide propagation direction that is perpendicular to the waveguide propagation direction of the first stage. a plurality of antenna elements distributed in an array of columns and rows in first and second dimensions, each antenna element having a waveguide propagation direction along a third dimension, wherein each antenna element comprises a common waveguide and a septum polarizer having a longitudinal axis extending in the third dimension and arranged to divide the common waveguide into a first waveguide (215a; 315a) associated with a first polarization and a second waveguide (215b; 315b) associated with a second polarization, wherein each of a first set of the septum polarizers (210-a) has the same orientation and is inverted by rotation by 180 degrees around the longitudinal axis of the septum polarizer relative to each of a second set of the septum polarizers (210-a) to form first groups of four adjacent first waveguides of the first waveguides arranged as two rows and two columns, and to form second groups of four adjacent second waveguides of the second waveguides arranged as two rows and two columns; and a waveguide feed network comprising: a first waveguide feed stage comprising a first plurality of waveguide combiner/dividers coupled between the four adjacent first waveguides of the first groups and first intermediate waveguides and a second plurality of waveguide combiner/dividers coupled between the four adjacent second waveguides of the second groups and second intermediate waveguides, wherein the first waveguide feed stage has a waveguide propagation direction that is substantially aligned with the third dimension; and a second waveguide feed stage coupled with the first intermediate waveguides and the second intermediate waveguides, wherein the second waveguide feed stage has a waveguide propagation direction that is perpendicular to the waveguide propagation direction of the first stage. a first waveguide feed stage comprising a first plurality of waveguide combiner/dividers coupled between the four adjacent first waveguides of the first groups and first intermediate waveguides and a second plurality of waveguide combiner/dividers coupled between the four adjacent second waveguides of the second groups and second intermediate waveguides, wherein the first waveguide feed stage has a waveguide propagation direction that is substantially aligned with the third dimension; and a second waveguide feed stage coupled with the first intermediate waveguides and the second intermediate waveguides, wherein the second waveguide feed stage has a waveguide propagation direction that is perpendicular to the waveguide propagation direction of the first stage.