What is the practical Axial ratios for linear and elliptical polarizations?

Hi,

We know that if an antenna is circularly polarized, its axial ratio is <3dB for the frequency range observed. Similarly what are the practical values for linear and elliptical polarization. Please don't provide infinity for linear polarization and very high value for elliptical polarization.

Warm Regards.

I believe it is > 6 dB for elliptical polarization. But, what is it for linear polarization?

Well, for linear polarization it is infinity though. Here is an example of a horn antenna

Thank you! I believe what you have shown are the ratios of minor axis to the major axis as the values are in -ve dB!