Two linearly polarized, orthogonal (right angle) light beams that are 90 degrees out of phase. Produced from unpolarized light by a linear polarizer aligned 45 degrees from a major axis of a quarter wave plate.
Two orthogonal linearly polarized waves of equal amplitude and 90 degrees out of phase are radiated simultaneously. The electric field vectors rotate around a circle. If the horizontal E field vector leads the vertical E field vector as seen in the direction of rotation, the polarization is said to be Clockwise Circular (right-hand circular polarization). If the horizontal E field vector lags the vertical E field vector as seen in the direction of rotation, the polarization is said to be Counter clockwise Circular.
The radiation of radio energy in a circular patterns similar to sound wave propagation, or the circular ripples in water caused by a stone being dropped into it.
Some satellites transmit both right-hand rotating and left-hand rotating signals simultaneously on the same frequency. This technique effectively doubles the channel carrying capacity of the satellite.
A mode of transmission in which signals are downlinked in a rotating corkscrew pattern.
Unlike many domestic satellites which utilize vertical or horizontal polarization, the international Intelsat satellites transmit their signals in a rotating corkscrew-like pattern as they are down-linked to earth. On some satellites, both right-hand rotating and left-hand rotating signals can be transmitted simultaneously on the same frequency; thereby doubling the capacity of the satellite to carry communications channels.
Is a method of radio energy emission where the electric and magnetic field vectors rotate about the central axis of radiation. See Left Hand Circular Polarization and Right Hand Circular Polarization.
In an antenna, where the tip of the field vector, as viewed in the direction of propagation, rotates either clockwise (right hand) or counterclockwise (left hand).
A special method of radio energy emission where the electric and magnetic field vectors rotate about the central axis of radiation. As viewed along the radiation path, the rotation directions are considered to be right-hand-circular (RHCP) if the rotation is clockwise and left-hand-circular (LHCP) if the rotation is counter-clockwise. Both right-hand rotating and left-hand rotating signals can be transmitted simultaneously on the same frequency; thereby doubling the capacity of the satellite to carry communications channels.
In electromagnetic wave propagation, polarization such that the tip of the electric field vector describes a helix. The magnitude of the electric field vector is constant. The projection of the tip of the electric field vector upon any fixed plane intersecting, and normal to, the direction of propagation, describes a circle. A circularly polarized wave may be resolved into two linearly polarized waves in phase quadrature with their planes of polarization at right angles to each other. Circular polarization may be referred to as "right-hand" or "left-hand," depending on whether the helix describes the thread of a right-hand or left-hand screw, respectively.
Used mainly on international satellites, circular polarization uses right-hand and left-hand rotation to distinguish between signals of opposite polarity. U.S. domestic satellites generally use vertical and horizontal polarization to distinguish separate signals. On some satellites both right-hand and left-hand signals may be transmitted simultaneously at the same frequency. This capability may effectively double the channel carrying capacity of a given satellite. Instead of positioning the microwave energy in a plane, whether vertical or horizontal, circular polarization is transmitted in a circular pattern, that rotates in either a clockwise or a counter-clockwise direction. Although your regular feedhorn can still pick up circularly polarized signals, you end up losing half of the available signal. This can make the difference between a noise-free picture and one that is not tolerably viewable.
In electrodynamics, circular polarization of electromagnetic radiation is a polarization such that the tip of the electric field vector, at a fixed point in space, describes a circle as time progresses. The name is derived from this fact. The electric vector, at one point in time, describes a helix along the direction of wave propagation (see the polarization article for pictures).