Dual band antenna pair with high isolation

A method of operating a multi-band wireless wide area network antenna apparatus, the method comprising:

• transmitting a first signal at a first frequency in a first range of frequencies from a first planar metallic antenna, the first planar metallic antenna resides on a first side of a substrate, the substrate has a ground plane on a second side;
• transmitting a second signal at a second frequency in a second range of frequencies from a second planar metallic antenna while transmitting from the first planar metallic antenna, the second planar metallic antenna resides on the first side of the substrate, the second signal transmitting orthogonal polarization to the first signal;
• and
• generating currents through a planar metallic parasitic element that resides on the first side of the substrate between the first planar metallic antenna and the second planar metallic antenna, the currents generated in response to the first signal, the currents causing the planar metallic parasitic element to create an electric field that provides electrical isolation between the first and second planar metallic antennas, wherein the planar metallic parasitic element is in the same plane as the first planar metallic antenna and the second planar metallic antenna, said same plane being parallel to the ground plane, the planar metallic parasitic element is electrically connected to the ground plane.

An apparatus comprising:

• a printed circuit board having a first major side and a second major side;
• a ground plane on the first major side of the printed circuit board;
• a first metallic microstrip antenna on the second major side of the printed circuit board, the first metallic microstrip antenna configured to radiate a first signal in a first range of frequencies;
• a second metallic microstrip antenna on the second major side of the printed circuit board, the second metallic microstrip antenna configured to radiate a second signal in a second range of frequencies, the second signal radiates orthogonal to the first signal;
• and
• a planar metallic parasitic element disposed between the first and second metallic microstrip antennas on the second side of the printed circuit board and configured to provide electrical isolation between the first and second metallic microstrip antennas, wherein the planar metallic parasitic element is in the same plane as the first metallic microstrip antenna and the second metallic microstrip antenna, said same plane being parallel to the ground plane, the planar metallic parasitic element is electrically connected to the ground plane.