Use this Antenna Directivity Estimator/Calculator to obtain the directivity of an antenna. The directivity of an antenna is the same as its gain, when its efficiency is 100%. This means that, when the losses of the antenna are or are assumed to be zero, you may use this tool as an Antenna Gain calculator.
To use this calculator, the azimuthal and elevation beamwidths need to be known or measured. To measure, estimate the arc width in degrees between the two adjacent -3dB (half power) points around the peak. Enter both entries to calculate the directivity. Note: this tool may fail to predict properly if the antenna being analyzed has more than one main peak. Any secondary peaks should be 6 dB or more lower (1/4 or smaller) the the main lobe.
You may use this antenna directivity estimator/calculator (antenna gain calculator) at your leisure. It is a Javascript application which runs on your browser, meaning that you do not need to download the code.
By Myers Engineering International, Inc.
