The waveguide structure is for determining Direction-of-Arrival of a signal received by first and second antennas spaced-apart from one another. The waveguide structure has a first input port connectable to the first antenna and connected to a first splitter; a second input port connectable to the second antenna and connected to a second splitter, the second input port being located adjacent to the first input port; a third splitter; and a fourth splitter. The waveguide structure has branches that connect input ports, splitters and output ports such that each output port provides a superposition of the signal received via the first antenna and the signal received by the second antenna. The waveguide structure has a phase shifting system that imparts at least a relative phase shift between the corresponding branches leading away from each corresponding splitter and has at least one cross-over junction formed between two of the branches.