interpretation of radiation pattern plot

HI
Please can anyone help me to interprete the radiation pattern plot! Here an exemple picture of radiation pattern of patch antenna at E and H plane. What informations we can extract . Thanks for help

Radiation patterns are graphical expression of how an antenna transmits elmag power into various directions in E and H planes (sometimes in other planes).
Calibrated pattern offers readings of maxima and minima in dB against a maximum power (main lobe).
Comparing E and H patterns offers the polarization feature of a particular antenna (if one polarization is desired). Circular polarization may be determined if E ad H power on main axis are close to equal.



Your patterns show almost equal gain of 19-20 dB on the main axis, and a god front-to-back ratio of >20 dB. It means that your antenna can also be used to generate circularly polarized wave on its main axis.
Also, that by rotating the antenna, power decrease vers. angle is smooth and the decrease is smooth: will require no exact pointing, or, can cover a wide solid angle if used as a transmit antenna.