microstrip antenna question, how to calculate antenna length

i want to use microstrip antenna for gsm modem, can anyone please tell me if thickness of copper will affect rf signal quality? and also how to calculate antenna length for microstrip antenna?

Hello

There are a set of design equations for length and width of the patch

Resonant Frequency=(3*10^8)/(2*Length*sqrt(epsilonr))

you should be able to calculate the length from here,in the above equation epsilonr represents the dielectric of the material.

Thickness of copper affects your impedance values,so matching can be a issue.but this is only for higher frequencies. at around 2GHz the impedance difference between .5 ounce and 1 ounce is around 2 ohms

Hope that was helpful.

Regards
Sajid Mohammed.

thank you for the formula.
my modem needs 50 ohm impedance match for antenna, i am using 2 layer board with with FR4, can you please tell how do i calculate trace length for 50ohm match?

You are welcome

Unfortunately it is quite difficult to write the formula here for two layer board without the help of math symbols.i will write you the equation on a document and forward it to your email here on eda.

Regards
Sajid Mohammed.

---------- Post added at 22:14 ---------- Previous post was at 21:01 ----------

Hello Do you have acess to Mathcad ?

Regards
Sajid Mohammed.