User's Manual

SIM800 Document
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4.2. Module RF Receive Sensitivity
The following table shows the module’s conducted receive sensitivity, it is tested under static condition.
Table 10: SIM800 conducted RF receive sensitivity
Frequency
Receive sensitivity（Typical）
Receive sensitivity(Max)
GSM850
-108dBm
-106dBm
EGSM900
-108dBm
-106dBm
DCS1800
-108dBm
-106dBm
PCS1900
-108dBm
-106dBm
4.3. Module Operating Frequencies
The following table shows the module’s operating frequency range; it is followed by the 3GPP TS 05.05 technical
specification requirement.
Table 11: SIM800 operating frequencies
Frequency
Receive
Transmit
GSM850
869 ~ 894MHz
824 ~ 849 MHz
EGSM900
925 ~ 960MHz
880 ~ 915MHz
DCS1800
1805 ~ 1880MHz
1710 ~ 1785MHz
PCS1900
1930 ~ 1990MHz
1850 ~ 1910MHz
5. Antenna interface
There are three antenna ports for SIM800, GSM antenna port named RF_ANT, Bluetooth antenna port named
BT_ANT, The RF interface of the three antenna ports has an impedance of 50Ω.The maximum gain of the
antenna gain should not exceed 3dbi considering the SAR radio.
 The input impendence of the antenna should be 50Ω, and the VSWR should be less than 2.
 It is recommended that the GSM antenna and the BT antenna be placed as far as better.
 The isolations of the three antenna should be bigger than 30db
5.1 GSM Antenna Interface
There is a GSM antenna pad named RF_ANT for SIM800 the connection of the antenna must be decoupled
from DC voltage. This is necessary because the antenna connector is DC coupled to ground via an inductor for
ESD protection.
The external antenna must be matched properly to achieve best performance, so the matching circuit is
necessary, the connection is recommended as following: