User's Manual

SIM800H Document
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It have according to reference trace and matching circuit testing all FCC items,and all items satisfy FCC
requirements.Only the reference trace and matching circuit is certified,
antenna design must refer to it, any other deviations require testing Class II applications as required by
FCC. The certified matching circuit as following:
5.1 GSM Antenna Interface
There is a GSM antenna pad named RF_ANT for SIM800H 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:
Figure1: GSM antenna matching circuit
R101，C101，C102 are the matching circuit, the value should be defined by the antenna design. normally R101
is 0Ω, C101 和 C102 are not SMD. The RF connector is used for conducted