Question on PCB thickness for RF circuit

Hi,

I have to route an RF circuit.

On a track of the PCB, there's a sinusoidal signal at 1.9 GHz.f

I'm gonna use ordinary FR4 substrate.

What would be the best thickness in terms of price and performances?


Thank you,
Enrico Migliore

1.6mm is standard and cheapest.But 1mm and 0.8mm can also be used with extra cost.

Performance with FR4 will be bad in the microwave range, independent of the substrate thickness. To achieve a specific impedance, you'll select a w/h ratio. Except for a cerrtain copper roughness and skin effect influence, the loss factor won't change with different h values.

Yes,Substrate thickness has an effect on trace impedance,you should keep a contant w/h ratio to meet your conatant impedance when change the sub thickness. Some simulation tools may help you,such as ADS,Appcad,etc.