Specifications

SIM7028 Hardware Design V1.00
www.simcom.com 35 / 48
default, the R1, R2 are 0Ω resistors, and the C1, C2 are reserved for tuning. The component D1 is a TVS
for ESD protection, and it is optional for users according to application environment.
The RF test connector is used for the conducted RF performance test, and should be placed as close as to
the module
’
s MAIN_ANT pin. The traces impedance between SIM7028 and antenna must be controlled in
50Ω.
Two TVS are recommended in the table below.
Table 20: Recommended TVS
Package
Part Number
Vender
0201
LXES03AAA1-154
Murata
0402
LXES15AAA1-153
Murata
5.3 RF Layout Design Guide
5.3.1 RF layout
 The length of RF trace between module and antenna should be as short as possible upon the antenna
position and trace loss, the module should be placed as close as possible to the main board edge.

The RF trace(micro-strip trace on top or strip trace in the inner layer) should be shielded by ground and
50Ω impedance.
 RF trace should avoid right angle and acute angle.
 RF trace should be shielded around GND.
 RF trace examples shown in the following figure, which isolated from other high-speed signal and
shielded by GND.
Figure 18: RF trace should be isolated from other signal trace
 Do not trace RF signal across or parallel with other signals
 If the interface of RF is SMA, GND should has some distance away from RF pads. Do not lay the
copper in all the layers on PCB