Gsm/Lte Antenna Design Guide - SimCom SIM7000 Hardware Design

4.2

GSM/LTE Antenna Design Guide

Users should connect antennas to SIM7000's antenna pads through micro-strip line or other types
of RF trace and the trace impedance must be controlled in 50Ω. SIMCom recommends that the
total insertion loss between the antenna pads and antennas should meet the following requirements:
Table 26: Trace loss
Frequency
700MHz-960MHz
1710MHz-2170MHz
2300MHz-2650MHz
To facilitate the antenna tuning and certification test, a RF connector and an antenna matching
circuit should be added. The following figure is the recommended circuit.
MAIN_ANT
模块
Figure 26: Antenna matching circuit (MAIN_ANT)
In above figure, the components R1, C1, C2 and R2 are used for antenna matching, the values of
components can only be achieved after the antenna tuning and usually provided by antenna vendor.
By 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 SIM7000 and antenna must be
controlled in 50Ω.
Two TVS are recommended in the table below.
Table 27: Recommended TVS
Package Part Number
0201 LXES03AAA1-154
0402 LXES15AAA1-153
SIM7000 _Hardware Design _V1.04
Loss
<0.5dB
<0.9dB
<1.2dB
RF connector
60
GND 61
Smart Machine Smart Decision
Matching circuit
R1 R2
D1
C1 C2
TVS
Vender
Murata
Murata
2018-1-31