Forum Post: CC1111-USB Dongle layout

Hi

I am designing my own device using CC1111 , for this purpose I am referencing the USB dongle reference design.

I face a problem with the impedance

I found this note in the reference design :

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PCB DESCRIPTION: 4 LAYER PCB 1.6 MM NOMINAL THICKNESS FR4

DOUBLE SIDE SOLDER MASK, DOUBLE SIDE SILKSCREEN, 8 MIL MIN TRACE WIDTH AND 8 MIL MIN ISOLATION , Dielectric constant for FR4 is 4.5

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but I don't know what the type and the thikness of Prepreg and what the Trace Thickness ?