As noted previously, the ideal helical monopole location is in the corner of the PCB. Note the corner mounting position on the PCB in the illustration on this slide in the radiation pattern of the XZ-PLANE. The object in the pattern is an image of a reference board with the surface mount antenna in the top left corner of the board. The E-Plane is in the same vertical plane as the length of the PCB; not broadside to the radiator. This illustrates the dependency of the ground plane as the ground plane and helical monopole both make up the aperture of the antenna. As the ground plane is reduced, the radiation efficiency also decreases. The helical monopole offers excellent omni-directional performance in the azimuth plane. Just as a dipole radiates omni directional with naturally occurring nulls in the zenith, so too is this evident in the helical monopole’s radiation pattern. Typical radiation efficiency for helical monopoles ranges between 50 to 55% peak efficiency.