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# how to find out the Co and cross polarization of the corrugated horn using hfss

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#### DIVYAROLI

##### Newbie level 5
hey i m attaching ma corrugated horn antenna design along wid reults....
pls any1 let me what is the level of cross n co polar polarization...

#### Attachments

• corrugated horn.rar
39.7 MB · Views: 314

you can set up an additional radiation far field setup which covers only a short section (say -10<theta<10) and compute antenna parameters over this region. i got the following results for your model. was the relationship between the magnitudes or rEx and rEy what you were looking for ?

ramanan.b

### ramanan.b

Points: 2
i want to know, how i should find out the cross polarization level of dis corrugated horn antenna using HFSS...

Linear polarization for your antenna is achieved along the X axis.

At boresight, dB(GainX) = 20 dB
The cross polarization to this will be dB(GainY) = -24 dB

So the cross pol level is around -44 dB which is very good *.

*note: I have not solved or checked your model for validity. I have merely interpreted the results provided in the attachment.

Points: 2

### ramanan.b

Points: 2
I am also working on corrugated horn antenna and I am getting co-pol(gainx) +20 dB and cross pol(gainy) -18 dB. But, problem is that I am getting peak in cross pol at boresight. Can you help me in finding reason for the same?

hey as i m interested in to test the cross and copolar level when corrugated antenna is verticaly polarised and horizontally polarized both.....
and how did u know it is lineraly polarized in X direction.....

I am also working on corrugated horn antenna and I am getting co-pol(gainx) +20 dB and cross pol(gainy) -18 dB. But, problem is that I am getting peak in cross pol at boresight. Can you help me in finding reason for the same?

Hi

I did not see this post till now.

As long as there is a large difference between co-pol and cross-pol, it should be fine. It is common to find a small peak at boresight for the cross-pol also. It depends on your antenna design and we cannot make any guesses without talking specifics.

- - - Updated - - -

hey as i m interested in to test the cross and copolar level when corrugated antenna is verticaly polarised and horizontally polarized both.....
and how did u know it is lineraly polarized in X direction.....

X, Y are just names labels given to the different axes. In your setup, the E-field vectors were all pointing and oscillating only along the X direction (thus linearly polarized along X).

This can also be seen through the component of E-field vector being maximum along X. (i.e. rEx >> rEy and rEx >> rEy at the far field observation point)

ramanan.b

### ramanan.b

Points: 2
hey as i am new and dnt have much experience with hfss.....
Will u help me how to change the E field vectors to Y directions ...so

One simple way is to rotate your input setup by 90 deg about the Z axis.

Then your modes will now also change their alignment and you will get the opposite linear polarization. (i.e. E aligned along Y)

ramanan.b

### ramanan.b

Points: 2
In the given design,corrugated horn is excited using circular wveguide which is excited using waveport and the number of modes used is 2 in +X and +Y direction,so how i could rotate my input setup in HFSS

Hi

I did not see this post till now.

As long as there is a large difference between co-pol and cross-pol, it should be fine. It is common to find a small peak at boresight for the cross-pol also. It depends on your antenna design and we cannot make any guesses without talking specifics.
Now, I am getting very good response. co polarization is 21 dB and cross polarization is now -62 dB

- - - Updated - - -

just by giving modes in reverse order. means, if you have define 1st mode in x direction, then replace it by giving it in y direction and 2nd one in the x direction in place of y direction. k?

Hi

I did not see this post till now.

As long as there is a large difference between co-pol and cross-pol, it should be fine. It is common to find a small peak at boresight for the cross-pol also. It depends on your antenna design and we cannot make any guesses without talking specifics.
Now, I am getting very good response. co polarization is 21 dB and cross polarization is now -62 dB

- - - Updated - - -

just by giving modes in reverse order. means, if you have define 1st mode in x direction, then replace it by giving it in y direction and 2nd one in the x direction in place of y direction. k?

Looks good to me.

ramanan.b

### ramanan.b

Points: 2

One simple way is to rotate your input setup by 90 deg about the Z axis.

Then your modes will now also change their alignment and you will get the opposite linear polarization. (i.e. E aligned along Y)[/QUOTE/]

we design inx-y plane then how to change input setup by 90 abt z?

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