1: Antenna gain : the ratio of the power density of the signal generated by the actual antenna and the ideal radiation unit at the same point in space under the condition of equal input power. It quantitatively describes the degree to which an antenna concentrates its input power. Obviously, the gain is closely related to the antenna pattern. The narrower the main lobe and the smaller the side lobe, the higher the gain.
2. Polarization of antenna: polarization of antenna :the direction of electric field strength formed when the antenna radiates. When the electric field component of the electromagnetic wave propagates, whether it is parallel to or vertical to the earth, thus there is a difference between horizontal polarization and vertical polarization. There are two polarization modes of antenna: vertical polarization (V) and horizontal polarization (H). The receiving of vertical polarization and horizontal polarization is to change the direction of the rectangular (rectangular) waveguide port of the feed to determine whether the receiving is vertical polarization or horizontal polarization. When the long side of the rectangular waveguide port is parallel to the ground, it receives vertical polarization, and when it is perpendicular to the ground, it receives horizontal polarization.