Hello,
AoA works well for field of view of -60° - +60°. Above these values, you will face wrapping issues on the PDOA (switching from -180 to +180 degrees), and you will face non-linearity issues. For such high angle, I would advise to retrieve the raw PDOA and run you own algorithm and look up tables to get the AoA. With that you will be able to compensate some non-linearity issues, but I would say, there is no magic and it is very difficult (impossible ?) to have a 180 degree Field of view with only one pair of antenna.