Shifting of Axial ratio value

[Diana S]

Sir/Madam ,


My resonating frequency is 1.6Ghz but my axial ratio resonating frequency is 1.11Ghz ...what is the reason for the shift of axial ratio value....and axial ratio bandwidth is very small when compared to the impedence bandwidth

 

[zorro]

Hi Diana,

Not necessarily the frequencies have to be coincident.
Please can you tell of which type is your antenna, and what definition are you taking for axial ratio resonance and axial ratio bandwidth?
Regards

Z

 

[Diana S]

Sir,
i am using a square patch antenna with suspended configuration...I have placed a foam between the ground plane and the dielectric..Can i know the reason for the shifting of axial ratio value....and my axial ratio BW is too low...how can i improve the axial ratio bandwidth

Hi Diana,

Not necessarily the frequencies have to be coincident.
Please can you tell of which type is your antenna, and what definition are you taking for axial ratio resonance and axial ratio bandwidth?
Regards

Z

 

[zorro]

So you are using a square patch for linear polarization, right? Or it is for circular polarization?
Again, what definition are you taking for axial ratio resonance and axial ratio bandwidth?

And what directions are you lookint at?
If I remember correctly, the cross-polarizartion (but not the axial ratio) has maxima in planes at 45º for an ideal square patch. This is inherent to the patch configuration.

Regards
Z