User's Manual

NOTE: The impedance of traces in Bold type must be 50Ω.
10.2. Matched RF Transmission Line Design
In PCB layout, a matched RF transmission line has a fixed characteristic impedance, which is called
Z
0
, from its source to its load. The source should have an internal resistance of Z
0
and the
resistance of matching load should close to Z
0
.
Since the impedance of M10’s RF_ANT port is 50Ω, the impedance of the RF transmission line
from this port to the antenna or the matching circuit should also be made to 50Ω.
More than twelve different types of transmission line can be created on a PCB simply by controlling
trace geometry, and some of them are shown in Figure 8.
Figure 8: M10 RF_ANT PCB layout
Customer may adopt one or certain types of them to design RF trace. Upon the demand of
application design, the number of PCB layer can be different such as two and four. Each type of
PCB has corresponding “stack-up”. The “stack-up” is the name given to the order of the various
etched copper foil and dielectric layers that are laminated together under pressure and heat to make
a PCB.
10.3. PCB Layout Consideration
PCB Layout is essential to the performance of customer’s product. Here are some rules that should
be followed:
 Impedance control