What are the important properties of circularly polarized waves?

(1) A circularly polarized wave is an instantaneous rotating field of equal amplitude, that is, the end point trajectory of the instantaneous electric field vector of the wave is a circle as viewed along its propagation direction.Thus, the basic principle of implementing a circularly polarized antenna is to generate two spatially orthogonal linearly polarized electric field components with equal amplitude and phase difference of 90 degrees.

(3) Any polarized wave can be decomposed into two circularly polarized waves with opposite directions of rotation.For example, in the airport baggage handling system, in order to provide high directionality and narrow beam to better identify objects within a certain range, the reader antenna is generally designed to be linearly polarized, and the label is placed in an indeterminate direction for reading and writing.The polarization characteristics of the antenna are required to achieve circular polarization of the tag antenna.Attention should be paid to the polarization characteristics of the antenna in RFID system applications.

(5) When a circularly polarized wave is incident on a symmetrical target (such as a plane, a spherical surface, etc.), the reflected wave becomes reversely rotated.That is, the left turn becomes right-handed, and the right-hand turn becomes left-handed.According to this property, a radar operating with circularly polarized waves has the ability to suppress rain and fog interference.