bandwidth calaculation

[aidin438]

Hi everyone.
I want to calculate bandwidth of a microstrip in unit cell mode with floquet port in cst but when I want to calculate from return loss graph there is no any -10 dB line I mean -10 dB line doesn't have any connection with the graph

 

[johnjoe]

Are you sure your sim is correct? Because s21,s12 has a maximum of -40db, quite low value?

 

[aidin438]

Are you sure your sim is correct? Because s21,s12 has a maximum of -40db, quite low value?

Thank you for your reply.
could you explain more about sim?I don't know what it means.I just want to calculate bandwidth.Is there another way to achieve that?

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Are you sure your sim is correct? Because s21,s12 has a maximum of -40db, quite low value?

May be you mean simulation.actually I'm not sure.the frequency is 10 GHz and the ground plane and substrate dimensions are 15*15 mm and the patch dimensions are 10*10 mm. Is there any problem with the patch dimensions?I think there is an equation to achieve dimensions in special frequency. Is it true?

 

[johnjoe]

Actually, i'm not very familiar with this type of antenna. Maybe your sim (simulation) is not correct. But the values of s-parameters loo quite strange.

 

[aidin438]

Actually, i'm not very familiar with this type of antenna. Maybe your sim (simulation) is not correct. But the values of s-parameters loo quite strange.

Many thanks sir.
what about this graph?how can i achieve bandwidth?

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Actually, i'm not very familiar with this type of antenna. Maybe your sim (simulation) is not correct. But the values of s-parameters loo quite strange.

sb told me that you have to draw -10 db line in order to find the bandwidth but in my graph there is no any -10 db line.

 

[johnjoe]

As I said, something wrong in your simulation. Maybe try to compare your work with other works.