dual feeding in a single patch

[sonia raj]

zorro,
In my result s11=s22 and s21=s12 but s11 is not equal to s12..is It right?

 

[zorro]

Yes, it's right.
s11 and s22 (not necessarily equal) indicate matching at te two ports.
s12=s21 indicate isolation between the ports.
Regards

Z

 

[sonia raj]

okk zorro..thanks everyone for your help..
after this when i will switch to next objective..i will ask for help

 

[sonia raj]

hello evryone for circular polarization axial ratip should be less than 3 dB right?but my axial ratio is not like this also i want to ask one more thing do i consider axial ratio at both port or only single one?

 

[zorro]

Axial ratio is not a characteristic that could be determined at port level. It's a characteristic of radiated field.
What result do you get?

Z

 

[sonia raj]

Axial ratio is not a characteristic that could be determined at port level. It's a characteristic of radiated field.
What result do you get?

Z

okk...i am enclosing my results here for axial ratio.

farfield axial ratio for 1st radiated field
farfield axial ratio for 2nd radiated field

now tell me how these are circularly polarized??
thanks

 

[zorro]

Sonia,

Why are there two different results?
Are you exciting the two ports separately?
Onthe other hand, the scale of the vertical axis is not clear for me. Can you clarify?
And please show the plot of directivity.

Z

 

[sonia raj]

yes there is two ports ..and m exciting these separately...what to do please tell me
vertical scale is showing axial ratio..
and here are the plots of directivity.

 

[zorro]

yes there is two ports ..and m exciting these separately...

In order to obtain circular polarization you must excite the two ports at the same time with 90 degrees phase difference!

vertical scale is showing axial ratio..

Of course... but it's id dB? in times?

and here are the plots of directivity.

It looks quite normal. There is only one, I see it is from port 1.
Axial ratio from port 2 looks strange.

what to do please tell me

You should study some basics about antennas.
When asking for help, you should give clear information. For example, it remains unclear how is the design.

Regards

Z

 

[sonia raj]

zorro,
here is the url of my design and rest i have tell u in msgs please check..
https://obrazki.elektroda.pl/4374353400_1397625052.png


thanks