HFSS Help on radiation patterns

Hello everybody.
I need some help very urgently.
I designed a stacked patch antenna, obtained its S11, VSWR, smith chart and all using HFSS v12.
Now i wish to obtain its far field radiation pattern. for that i already created far field setup and infinite sphere with Φ having two values i.e. 0 and 90 deg while θ varying over the range from -180 to 180 deg.
I consequently computed the antenna parameters with sweep option at my antenna's resonating frequency.
Problem:
When i create a report to view the patterns, the problem start here; I don't know what option should i select to obtain the correct radiation pattern plot.

I am aware of Ludwig's 3rd definition for co-polar and cross-polarization. So i inserted the two formulas in the output variable option as:

Ecopol = Eθ cos φ − Eφ sin φ
Expol = Eθ sin φ + Eφ cos φ

and obtained results for phi=0 and 90 deg separately
Now, i want to know, whether the option rEL3X, rEL3Y are the same same the above formula?
Do these above plots represent the Radiation pattern curves or simply rETotal (dB) curve is for radiation pattern?

Please...Please anyone reply soon, i am pretty much confused and in need of immediate help in this regard.

Thanks in advance

Hello

When we look at the radiation patter we are looking at the power radiated in the far field point. rEtotal is the radiated E field, which is part of the equation. Power according to the poynting theorem is a cross product of E and H fields.

Radiation pattern here means Gain(Total). and more over when you set up the radiation sphere,i would recommend you setup a sphere not a sphere or points on a sphere.what do i mean by this
a sphere here is meant by theta=0 to 360(-180 to 180) and similar values for Phi as well.

Hope that helps

Regards
Elchiquito

Thanks for reply Elchiquito. I clearly got your point, but i did not understand you on one point, what should be the range of phi?
Plus please do comment on the co-polar and cross polar curves with reference to my original post.

Thanks again.

Range of Phi, i tend to take it from 0 to 360 as well so i get a complete sphere.

Cross polarization (sometimes written X-pol, in antenna slang) is the polarization orthogonal to the polarization being discussed. For instance, if the fields from an antenna are meant to be horizontally polarized, the cross-polarization in this case is vertical polarization. If the polarization is Right Hand Circularly Polarized (RHCP), the cross-polarization is Left Hand Circularly Polarized (LHCP).

When we talk about co and cross polarization in a patch we are looking at two different planes, one with the E-plane and one containing the H-plane.

Hope that helps

Regards
Elchiquito

Thanks again for reply..but one thing i am still unsure is to take phi range to 360 deg. It is because while simulating using hfss, it uses phi=0 deg and phi=90 deg as its reference points to calculate E and H plane patterns (correct me if i am wrong). What i mean is phi=0 corresponds to E plane which has its own cross and co-polar curves while phi=90 deg represent H-plane curve with both cross and co polar curves. This is what i understood from ludwig's 3rd definition and formula (already given in my original post) but you are saying that E plane and H plane curves form co and cross polar curves.


Next i also want to know, how to investigate what is the type of polarization of my antenna. Is it just signified by the orientation of the main lobe of radiation pattern.

Please correct me wherever i am wrong.


Thanks and reagards

ok. Here we go again, range of the Phi variable doesnt have anything to do with co and cross polarization, i was talking about setting up the radiation sphere. how would you draw a sphere by integrating two circles right? how many degrees do you have in each circle 360 degrees?

coming back to your question about co and cross polarization. co polarization is the polarization that you are intending and cross polarization is the orthogonal polarization to the intended polarization. for instance let's say your antenna is vertically polarized(co polarization) what would be the cross polarization? horizontal polarization(right) which plane does it fall into?

yes you are right when you check for cross and co polarization, you are looking at their values in each plane.

How do you investigate the polarization of your antenna by checking for the axial ratio.

Regards
Elchiquito

elchiquito said:

ok. Here we go again, range of the Phi variable doesnt have anything to do with co and cross polarization, i was talking about setting up the radiation sphere. how would you draw a sphere by integrating two circles right? how many degrees do you have in each circle 360 degrees?

coming back to your question about co and cross polarization. co polarization is the polarization that you are intending and cross polarization is the orthogonal polarization to the intended polarization. for instance let's say your antenna is vertically polarized(co polarization) what would be the cross polarization? horizontal polarization(right) which plane does it fall into?

yes you are right when you check for cross and co polarization, you are looking at their values in each plane.

How do you investigate the polarization of your antenna by checking for the axial ratio.

Regards
Elchiquito

Click to expand...

thank you for the help and being so patient..

My last question, at what phi valu should the axial ratio be plotted when my radiation space has both theta and phi in the range of 360 deg. Rest, how to investigate what the polarisation is, i got from the help file in hfss
best regards