LPM2100 mg NB Module Hardware User Guide
Shanghai Yuge Information Technology Co., Ltd.
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Chapter 4. Overall RF technical indicators
4.1 Chapter overview
The LPM2100 mg series module RF overall technical specifications include the
following sections
：
Antenna design;
RF PCB design;
RF connector;
working frequency;
Conducted transmission power and receiving sensitivity;
RF power consumption characteristics.
4.2 Main antenna and Bluetooth antenna
The LPM2100 mg series module provides two antenna interfaces, one for the main
antenna interface and one for the Bluetooth antenna interface (reserved). In the circuit design,
the trace between the module and the antenna must be guaranteed to 50 ohms.
The antenna is a sensitive device that is susceptible to the external environment. For
example, module size, antenna position, footprint size, and surrounding grounding can all
affect antenna performance.
The module antenna pins are defined as follows
：
Table 4-1 RF Pin Definitions
Pin Pin name IO Functional description
Remarks
26
BT_ANT IO Bluetooth antenna interface
(reserved)
50
Ω
characteristic impedance
35
RF_ANT IO RF antenna interface
50
Ω
characteristic impedance
The 35-pin of the LPM2100 mg series module is the main antenna interface. To facilitate
the debugging of the antenna, it is necessary to add a
π
-type matching circuit to the
motherboard, and take the 50-ohm impedance line. The recommended circuit is as follows
：
