I am trying to design a Circular polarized Antenna. We know that the criteria for a circularly polarized E-field  :

• The E field should have to components
• The two components should be equal in magnitude
• The two components should be out of phase by 90 degrees

Due to these facts, the axial ratio of the circular polarized field should be 1 ( 0 dB). However, in antennas world, it is acceptable that we can consider an antenna as circullar polarized even if its Axial ratio reaches 3 dB as a maximum. The below figure shows the designed antenna axial ratio  :  

As we can see the axial ratio is drawn as a function of theta and phi. I need to understand how is the axial ratio is dependent on theta and phi? and if the antenna is circularly polarized according to this figure or not?

I am trying to design a circular polarized antenna. We know that the criteria for a circularly polarized E-field:

• The E field should have to components
• The two components should be equal in magnitude
• The two components should be out of phase by 90 degrees

Due to these facts, the axial ratio of the circular polarized field should be 1 ( 0 dB). However, in antennas world, it is acceptable that we can consider an antenna as circullar polarized even if its sxial ratio reaches 3 dB as a maximum. The below figure shows the designed antenna axial ratio: 

As we can see the axial ratio is drawn as a function of theta and phi. I need to understand how the axial ratio is dependent on theta and phi and if the antenna is circularly polarized according to this figure or not.