High VSWR at Notch Frequency

[KawtherHamad]

Hello All,


I drew an antenna as in one of the papers. I analysed it, and created the VSWR graph. It was as below



A very high VSWR at the notch frequency. The VSWR in the paper was about 26. Why did i have a very high VSWR at the notch frequency?


Regards,
Kawther Hamad,

 

[biff44]

you have an antenna that is well matched at EVERY frequency but one. quick, patent it

 

[chuckey]

That what notch filters do, reject power. If you need a good VSWR, you need an acceptance filter in parallel with the through path with a load, so at the "notch" frequency the power is just diverted into the load.
Frank

 

[KawtherHamad]

you have an antenna that is well matched at EVERY frequency but one. quick, patent it

I do not think this result is a true or simulating practical antenna. I think it is a matter of HFSS settings. The result from the paper is a maximum VSWR of 26 not 125!!.

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That what notch filters do, reject power. If you need a good VSWR, you need an acceptance filter in parallel with the through path with a load, so at the "notch" frequency the power is just diverted into the load.
Frank

the point is that i want to obtain a result that is similar to the paper. It is given in the paper that the maximum VSWR is 26 it is not 125. I think i should change some settings in my file. I do not know what are theses settings!

 

[aaron_do]

Hi,


both VSWR of 26 and 125 are very large. An analogy would be infinity and infinity + 1. Perhaps the difference is just some material setting resulting in your circuit having higher Q-factor.


regards,
Aaron