simple question about IE3D & Circular microstrip antenna

[atul_microwaves_antenna]

circular microstrip antenna

Hi,
I am trying to simulate a basic 2.45GHz circular microstrip antenna in IE3D. Bascially I am confused about the basic structute which IE3D is showing to me. I want to simulate a (only air filled) circular patch antenna which is to be fed by Coaxial feed? I searched for it but it seems it is not possible. Actully I will short ground plane (finite or infinite) to patch itself.That is the idea. I have used formulae from Balanis book to calculate radius of patch. My question is, dose probe feed is same as coaxial feed? .
In the 3D view of patch in IE3D, it shows only patch of 3.34cm radius but when I try to define port by probe feed, it dosen't work? Can anyone help me.
Thank you.

 

[jian]

circular shape with inset feed

Hi, Atul:

1. The probe-feed is for coaxial fed structure. It is very accurate and it is demonstrated in many papers.

2. There are examples in the IE3D Manaul and you can access the electronic version in the HELP menu of MGRID. Alos, there are examples in the Zeland Virtual Training in the Download of www.zeland.com. The Zeland Virtual Training contains movies showing you how to build structures.

Regards,

 

[balaguru thavamani]

tuning variable ie3d

hi atual,

Probe fed example was given in Chapter16th of IE3D manual.I think this will help

u.In 3D view of Probe fed patch only 3D polygon'll be displayed but not the port

number.

Added after 15 minutes:

If u've further prob in simulating this,send me the strucuture let me try.

 

[atul_microwaves_antenna]

microstrip ant

Thank you sir,
I am attaching the structures which I have tried it out.One is center fed and other is edge feed probe.I am also attaching a IEEE paper which says that inset feed location for matching is done using IE3D.I have tried to check it out but I cudn't find it in IE3D.Dose IE3D has this facility? I have checked help also, but not able to find if it is these. Can u help me in investigating it further?
Do you know how to find the exact location(depth and width) of inset of a circular patch? I have found out for reactangular patch (that too not for air core) but search is going for circular patcha also.Please look into those two basic designs:
Data are:
Air core, radius:3.34 cm,Freq=2.45GHz,h=0.1588cm
I tried it from Balanis example from Microstrip antenna chapter for circular aperture.

 

[atul_microwaves_antenna]

simple circular microstrip antenna

Sir,
uploading the diagrams.Center and edge fed coaxial feed.
Data:
air core, radius=3.34cm,h=0.1588cm,coaxial radius=0.20cm(Chosen randomly)
Thank you.

 

[balaguru thavamani]

Re: simple question about IE3D & Circular microstrip ant

hi atul,

I've simulated the given structure as per given dimensions in IEEE paper .

Its giving good result expect some offset in frequency.

I've enclosed the structure and its result go thr this and apply the same for

2.45GHz.

 

[atul_microwaves_antenna]

Re: simple question about IE3D & Circular microstrip ant

Sir,
I have a very basic question. How they have designed such an inset fed matching network? I mean the depth and length.Will it be same for 2.45GHz? Pls give me some hints to design matching networks for circular microstrips antennas.

 

[jian]

Re: simple question about IE3D & Circular microstrip ant

HI, Atul:

Her is an IE3DLibrary project with the patch radius as a tuning variable. You can modify the model with the inset feed's dimensions as tuning variables. It is hard to define the tuning variables in the standard layout editor MGRID while you can achieve it easily using IE3DLibrary.

Best regards,

 

[atul_microwaves_antenna]

Re: simple question about IE3D & Circular microstrip ant

Sorry Sir,
I didn't get you exactly. What is this IE3D project..? I didn't understand the first line of what you have written.
Thank you.

 

[jian]

Re: simple question about IE3D & Circular microstrip ant

Hi, Atul:

I think I forgot to attach the IE3DLIBRARY project file to you. IE3DLIBRARY is the 2nd layout editor for IE3D (the 1st one is MGRID). MGRID is based upon polygons and it is flexible for general shapes you can create using polygons. IE3DLIBRARY is more for parameterization. For the circular patch antenna with inset feed, it is very easy to build the structure and parameterize it on IE3DLIBRARY. Here are the IE3DLIBRARY files again. The cir_patch1.ie3 is the original one with the patch radius parameterized. The cir_patch2.ie3 is a new one with radius, the gap width and the depth parameterized.

Best regards,

 

[atul_microwaves_antenna]

Re: simple question about IE3D & Circular microstrip ant

Thank you sir.
I am checking it out.

Added after 5 hours 41 minutes:

Ok Sir,
I got a simple question. Can we simulate a finite ground structure in IE3DLIBRARY? If yes then can u pls let me know.I checked it out and tried to modify the Z=0 plane conductivity from 4.9*10^7 to 0 and then simulated it.It gave better results except the directional pattern. The direction pattern is on shape 8 if I make the above change.For infinite conductivity ground plane there is no lower half lobe of pattern 8.

 

[jian]

Re: simple question about IE3D & Circular microstrip ant

Hi, Atul:

Please see the attached files.zip. It contains the cir_patch2_finite.ie3, an IE3DLIBRARY project for a finite ground plane model with parameterized patch radius, gap and depth.

Best regards,

 

[balaguru thavamani]

Re: simple question about IE3D & Circular microstrip ant

Hi Atul,

In case of infinite Ground plane all waves will be reflected back which leads

to increase in directivity and hence there will be no back lobes.