One antenna module includes a first circuit board and a second circuit board connected to the first circuit board. The antenna module includes a first antenna disposed on the first circuit board. The antenna module also includes a second antenna disposed on the second circuit board. The second circuit board has a first side and a second side opposite the first side. The second antenna includes a first parasitic strip and a second parasitic strip. The first parasitic strip is disposed on the first side of the second circuit board, and the second parasitic strip is disposed on the second side of the second circuit board.