An electronic device (100) includes an antenna system (150) having two antennas (110, 120). A first antenna (110) has a first antenna element (111) positioned near a first corner (191) of a planar, rectangular ground plane (165) and a second antenna element (115) positioned near a second corner of the ground plane that is diagonally across from the first corner. A second antenna (120) has a third antenna element (121) positioned near a third corner (193) of the ground plane that is adjacent to the first corner and a fourth antenna element (125) positioned near a fourth corner (195) of the ground plane that is diagonally across from the third corner. At low-band frequencies, the antenna elements (111, 115) of the first antenna (110) are driven out-of-phase relative to each other. Similarly, at low-band frequencies, the antenna elements (121, 125) of the second antenna (120) are driven out-of-phase relative to each other.