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ok i did not get any reply to the thread posted my but i did get the answer.For the viewers i am posting it here
Advantages of Circular Polarization
Reflectivity: Radio signals are reflected or absorbed depending on the material they come in
contact with. Because linear polarized antennas are able to “attack" the problem in only one plane, if the reflecting surface does
not reflect the signal precisely in the same plane, that signal strength will be lost. Since circular polarized antennas send and
receive in all planes, the signal strength is not lost, but is transferred to a different plane and are still utilized.
Absorption: As stated above, radio signal can be absorbed depending on the material they come in contact with. Different
materials absorb the signal from different planes. As a result, circular polarized antennas give you a higher probability of a
successful link because it is transmitting on all planes.
Phasing Issues: High-frequency systems (i.e. 2.4 GHz and higher) that use linear polarization typically require a clear line-ofsight path between the two points in order to operate effectively. Such systems have difficulty penetrating obstructions due to
reflected signals, which weaken the propagating signal. Reflected linear signals return to the propagating antenna in the
opposite phase, thereby weakening the propagating signal. Conversely, circularly-polarized systems also incur reflected signals,
but the reflected signal is returned in the opposite orientation, largely avoiding conflict with the propagating signal. The result is
that circularly-polarized signals are much better at penetrating and bending around obstructions.
Multi-path: Multi-path is caused when the primary signal and the reflected signal reach a receiver at nearly the same time. This
creates an "out of phase" problem. The receiving radio must spend its resources to distinguish, sort out, and process the proper
signal, thus degrading performance and speed. Linear Polarized antennas are more susceptible to multi-path due to increased
possibility of reflection. Out of phase radios can cause dead-spots, decreased throughput, distance issues and reduce overall
performance in a 2.4 GHz system.
Inclement Weather: Rain and snow cause a microcosm of conditions explained above (i.e. reflectivity, absorption, phasing,
multi-path and line of sight) Circular polarization is more resistant to signal degradation due to inclement weather conditions for
all the reason stated above.
Line-of-Sight: When a line-of-sight path is impaired by light obstructions (i.e. foliage or small buildings), circular polarization
is much more effective than linear polarization for establishing and maintaining communication links.