Radiation pattern refers to the spatial distribution of the antenna’s radiated energy in free space, represented in polar coordinates. Directivity is defined as the power in the main beam of an antenna in a particular direction. The higher the antenna’s directivity, the narrower the antenna’s pattern in a certain direction. Null is a dip in the gain of the antenna in a particular direction. Typically high gain antennas are directional in nature, which generally applies to a good performance in one direction – where peak gain appears; and compromised performance in others – where nulls would be observed. High gain antennas typically are not omni-directional, and thus are not recommended for handheld applications.