Panasonic PAN9420 Design Manual page 12


3.8.2 RF Trace
Ensure that the RF trace impedance is nearly 50 . It is recommended to use a Coplanar
Waveguide with Ground (CPWG) design. The impedance is related to the trace width, the
distances of the trace to the ground layers and the material of the PCB.
The following requirements shall be met:

Trace impedance of 50 

Trace length shall not exceed 2 cm

Via fence around the trace

Crossing no other lines (power supply, interfaces or clock traces)
Example 1: 50  Coplanar Waveguide with Ground on SDIO Adapter
Design Guide Rev. 1.0
PAN9420 Wi-Fi Module
Trace width
Trace distance to ground
Substrate thickness
Effective Permittivity
Loss Tangent
3 PAN9420 Module
W = 180 µm
S = 150 µm
H = 80 µm
��
= 3.9
��
tan �� = 0.015
Page 12