Microwave links, specifically those used for wireless communication, can utilize different polarizations for several reasons related to signal propagation and interference mitigation. Here are a few key points:
Signal propagation: Electromagnetic waves, including microwaves, have different polarization orientations. The polarization of a wave refers to the orientation of its electric field vector as it propagates. By employing different polarization orientations for microwave links, network operators can take advantage of diverse propagation characteristics. This can help optimize signal reception and minimize interference in different environments.
Interference reduction: Microwave links often operate in crowded frequency bands where multiple links coexist. Using different polarization orientations can help reduce interference between adjacent links. When links in close proximity have orthogonal (perpendicular) polarizations, the interference caused by cross-polarization can be minimized.
Diversity reception: Polarization diversity can improve the reliability and performance of microwave links. By transmitting the same information using different polarizations simultaneously, the receiving antenna can capture the signal from multiple angles. This helps mitigate the effects of polarization fading, caused by changes in the polarization of the received signal due to reflections or multipath propagation.
Signal optimization: In certain situations, the polarization of the microwave link can be adjusted to optimize signal strength and quality. By aligning the polarization of the transmitting and receiving antennas, the signal can be maximized, leading to better overall performance.
It's important to note that the choice of polarization for microwave links depends on various factors, including the specific application, environmental conditions, interference sources, and system design considerations. Network planners and engineers evaluate these factors to determine the most suitable polarization scheme for a given microwave link deployment.