MEIG SLM 320 - Antenna interface; 5.1 Introduction to Antenna Interface; 5.2 Radio frequency reference circuit

MeiG_SLM320_Hardware Design Manual
MeiG Smart Technology Co., Ltd
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5 Antenna interface
SLM320 module design interface, there are three antennas, the antenna impedance 50Ω.
Table 19 Definition of pin of antenna interface
Pin Name Pin Number Description I/O Remark
ANT_MAIN 49
main antenna port IO 50Ω impedance
BT_ANT 35 WIFI/BT antenna port IO
50Ω impedance
ANT_GNSS 47 GPS antenna port IO 50Ω impedance
5.1 Introduction to Antenna Interface
SLM320 provides three antenna pins: ANT_MAIN and ANT_WIFI/BT to improve the product's TDD-LTE/
FDD-LTE, WIFI/BT transceister performance. It is recommended to use with the module, RF connector
match 50 Ω impedance of the antenna.
Note:
In order to ensure the communication capability of all frequency bands, please connect all antennas.It is
recommended that applications carefully select RF wiring. RF wiring needs to be selected with minimal
loss. RF wiring for RF loss requirements is recommended as follows:
 GSM900 <0.6dB
 DCS1800 <1.0dB
 TDD-LTE<1.2dB
 FDD-LTE<1.2dB
 WIFI/BT<1.2dB
 GNSS<1.0dB
5.2 Radio frequency reference circuit
The reference circuit for antenna connection of ANT_MAIN, ANT_WIFI/BT is shown in the figure below.
In order to obtain better RF performance, the following four points should be paid attention to when
designing schematic diagram and PCB layout:
1. Schematic design, near the module RF port reserved type matching circuit, capacitor default not
attached;
2. Schematic design, redundant RF connectors between the RF port of the module and the antenna,
used for certification test, RF connectors are not attached after mass production and delivery;
(Reference: RF Connector -1P-H176);
3. Schematic design, type matching circuit is reserved near the antenna end, capacitor is not affixed