How to test circular polarized antenna

Hi,
How to identify polarization of any antenna by testing? How to test circular polarized antenna ?

Thanks

Hi,
Kindly check this up..
Antenna Polarization Measurements

Thanks vinoth, but my question is by seeing radiation pattern of the test antenna is it possible to tell the test antenna is CP or LP ?

For testing CP antenna? what type of Reference antenna i should use?

hi
by the shape of antenna and its excitation u can fund the type of polarization of antenna too fast

Based on observing radiation pattern of the test antenna mostly is not enough to determine whether or not the antenna tested is CP. For example u achieved two radiation patterns which are measured perticular to each other. Of course CP requires these two radiation pattern to be the same, however the phase relationship is missing hence not only CP but also 45-deg slant LP can lead to such results.

It would be convenient to use LP antennas to test CP antennas.