differential transmission line impedance matching

[Fenglong]

Hi,

We are trying to reuse the RF frontend design provided in reference design of PCA10000-nRF51822 Development Dongle 2_0. But because we have different board thickness, and different manufacture capability, how to control the differential transmission line impedance (travelling out from the Nordic ANT1 and ANT2 pins and ending at the discrete LC matching network)?

To be specific, we use the same length and width of the transmission line as the reference design does. But we still need to tell the PCB manufacture about the impedance value they are going to control.

thanks, Fenglong

[FormerMember]

Hello,

For PCB thicknesses of 0.8 mm to 1.6 mm there are hardly any differences, so it is not necessary do any changes to the width of the transmission line. What is important is to keep the length of the transmission lines as short as possible, in order to decrease the series inductance due to the length of the transmission lines and the capacitance to ground.

Regards, Kristin