Prototyping pcb nrf

[Juniorprogrammer]

Hi, 

I'm a student and this is my first project on RF. I'm prototyping my own custom board. I did read in the papers of the quarterwave 2.45 GHz antenna that the PCB should be fabricated on a 1.6 mm FR4 substrate. Also does it says that the typical dielectric constant have to be Et of 4.4 at 2.45GHz. Is this typical dielectric constant something that I also have to choose by manufacturing or is it standard for FR4 substrate. 

Kind regards,

JP

[Kaja]

This can vary, and it's okay if it's not 4.4. 

you just have to make sure you use your numbers when you calculate the impedance of the RF path in your design. Making sure the RF path, form radio to antenna, is a 50 Ohm transmission line, a coplanar waveguide. 

You can use a calculation tool like AppCad to do this. 

Best regards,
Kaja