 Hey everybody, it's Tasos with RF Elements and today we're talking about antenna polarization. One of the most important parameters of an antenna is its polarization. It's a natural property of any antenna. Polarization dictates in which plane the fields of the transmission signals are changing. And polarization is dictated by a antenna designer. Horizontal and vertical are linear polarizations as well as slant or dual slant, where slant means that the fields are changing in planes rotated most commonly by 45 degrees relative to horizontal and vertical polarizations. Most commonly, antennas have linear polarization. That means that the field of the transmitted signals are changing in a line. The vast majority of antennas for WISP networks are linearly polarized. To achieve the best results, antenna polarizations must match. Horizontally polarized antennas communicate perfectly with equally polarized antennas on the other end of a link. As the rotation angle between antennas increase, the level of received signal decreases because of the physics of electromagnetic wave. This is why orthogonal polarizations provide isolation and creates additional communications channels at the same time. In the real world, isolation between horizontal and vertical is not perfect. Antennas with two polarizations have a parameter called cross polarization isolation, which tells you how well the H polarized antenna system and the V polarized antenna systems are separated. The higher the isolation, the better. For more interesting facts on RF and how antennas work, check out our future videos.