User's Manual

Bluegiga Technologies Oy
Page 30 of 41
Figure 14: Typical 50 trace for WF111-N
A transmission line impedance calculator, such as TX-Line made by AWR, can be used to approximate the
dimensions for the 50 ohm transmission line. Figure 15 shows an example for two different 50 ohm
transmission lines.
FR4, ε
r
= 4.6
Prepreg, ε
r
= 3.7
W = 0.15 mm
h = 0.076 mm
G = 0.25 mm
GND stitching vias
RF GROUND
RF GROUND RF GROUND
RF GROUND
FR4, ε
r
= 4.6
h = 1 mm
W = 1.8 mm
MICROSTRIP
CPW Ground
Figure 15: Example cross section of two different 50 ohm transmission line