Microstrip antenna design problem..plzzzzzzz

[alan6449]

ivan...
i have problem in determine coax size desin..can guide me

 

[srikanth805]

can any one tell me the power handling capacity of microstrip patch antenna.....
if my antenna size is 10x10 and patch size 4.8x4.8 coaxial feed

can u suggest any general formulae for calculating theee

 

[alan6449]

any suggestion

 

[Ivan_]

Alan, did u finalize the proj? Upload the file so I can check it. Concerning the coax, just simply get a datasheet of a generic 50 ohm SMA coaxial launcher and use the radius and dielectric material they indicate to obtain a 50ohm port impedance (usually some kinda teflon or a compound of teflon with another material, with a 2.1 permittivity, about...). Do u want to replace the hfss wave port with a coax launcher or u just need info for the prototype?

Waiting for the file...

Ivan.

 

[alan6449]

i already send the file

 

[Ivan_]

Where? I did't get anything by email. Post it on the forum.

 

[alan6449]

i sent through pm....did u get?

 

[plasma]

alan 6449

did you look at ?

pl

 

[Ivan_]

Alan,
I looked at ur design. Well, it looks pretty good, I mean it seems boundaries, excitation are correctly assigned. Dual resonance is ok as well as a low-level cross-pol. Resonances are not so matched, I mean I usually consider an optimal matching when reach -30dB at least, 'cause usually in measurements u may find even 10dB of difference (systematic and random measurement errors, manufacturing error, etc. etc.). Anyway, if I were you, I would be quite satisfied. Just one thing: even though those unissigned rectalnles don't affect sim results, drawing results a bit untidy!!! If u subtract an object from another in order to get a void and u don't tip 'clone object', subtracted object will disappear from a main drawing, resulting in a tidier drawing. That's just for nicety, I'm a bit too meticulous...

Hope this helped...

I.

 

[alan6449]

tq very much ivan....do u have any idea how to matched Resonances optimal

 

[Ivan_]

Usually u may find the geometrical params iif sma n datasheets. Anyway, u can reproduce a simple 50ohms coax launcher with the following parameters:

material: teflon based (epsR=2.08 );
copper conductor diameter: 0.9mm;
dielectric diameter:3mm;

I got these params using the TRL tool in Ansoft Designer.

Apply a PEC boundary on the outer face of the diel and that's it!!!

A way to remove connector contribution during S params measurement is to change ref plane after calibrating the VNA. Get a connector and paint the surface containing the pin launcher with conductive ink. After that, the pin will be shorted with coax ground. Then connect this connector to the calibrated VNA and press ref plane --> auto. We have an Anritsu VNA, actually I don't know if this feature is present in other brands' VNA...

I.

 

[srikanth805]

hi alan if u r done with ur project can i hav a luk at that...
my project is some wat related 2 it

 

[Ivan_]

Alan, try to send ur new design. I think next week I can find an hour to have look at it.

I.