Advantages of Circular Polarization | Disadvantages of Circular Polarization
This page covers advantages and disadvantages of Circular Polarization and its basics. It mentions benefits or advantages of Circular Polarization and drawbacks or disadvantages of Circular Polarization.
Introduction Polarization refers to directional aspects of E-field (i.e. electric field) of EM radio waves. It allows frequency reuse to enhance satellite bandwidth capacity by allocating same frequency at different polarizations i.e. linear and circular.
What is Circular Polarization?
The polarization in which E field radiates energy in both the horizontal plane and vertical plane and in all the planes in between is known as circular polarization. In this polarization, electric field has two linear components which are perpendicular to each other with equal amplitude and 90 degree phase difference. The resulting E-field rotates in a circle around the direction of propagation. Based on direction of rotation there are two types viz. RHCP and LHCP. Circularly polarized light signal can be generated by passing linear polarized light signal through quarter wave plate (λ/4) at angle of 45 degree to the optical axis of plate.
• RHCP (Right Hand Circular Polarization) : In this type, electric field rotates clockwise as seen by an observer
towards whom the wave is moving. This type is shown in the figure.
• LHCP (Left Hand Circular Polarization) : In this type, electric field rotates counterclockwise as seen by an observer towards whom the wave is moving.
Benefits or advantages of Circular Polarization
Following are the benefits or advantages of Circular Polarization:
➨No polarization adjustment is required as it is fixed using OMT (Orthomode Transducer).
➨There is less chance of cross pol interference.
➨RFID reader does not have to be on the same plane and similar heights as RFID tags unlike linear polarization RFID reader.
➨RFID reader does not require to know the tag orientation unlike linear polarized RFID reader. Hence it is used for applications where one does not know the orientation of RFID tags while reading the data.
Drawbacks or disadvantages of Circular Polarization
Following are the drawbacks or disadvantages of Circular Polarization:
➨It makes cost of antenna system higher.
➨It offers slightly lower cross pol isolation.
➨It offers shorter read range for RFID reader compare to linear polarization.
Refer advantages and disadvantages of Linear Polarization >>.