What are the main causes for side lobes in radar beams?

Side lobes in radar beams primarily arise due to diffraction and interference. Diffraction refers to the bending of radar energy around edges or obstacles, resulting in the spreading of the radar beam beyond the main lobe. This phenomenon can lead to energy being radiated in unintended directions, forming side lobes.

Interference plays a crucial role as well, particularly when multiple waves interact with each other. In radar systems, when waves scatter off various surfaces or objects, they can combine constructively or destructively, leading to the formation of side lobes in the radar display. These side lobes can sometimes cause confusion by picking up signals from targets that are not located in the radar’s main sensing direction.

In contrast, the other options incorporate elements that do not directly contribute to side lobe formation as effectively as diffraction and interference. For example, absorption and loss are related to signal strength and wave propagation but do not create side lobes in the radar pattern. Understanding the roles of diffraction and interference helps in grasping the complexities of radar signal behavior and the challenges faced in interpreting radar data.