Antenna Interface; Antenna Installation - Quectel M12 Hardware Design

M12 Hardware Design

4. Antenna interface

The Pin 43 is the RF antenna pad. The RF interface has an impedance of 50Ω. A reference circuit
is shown in the following figure. In order to adjust RF performance, it should reserve a П-type
matching circuit. By default, the resistance of R1 is 0Ω and capacitors C1 and C2 are not soldered.
Module
RF_ANT

4.1. Antenna installation

M12 provides an RF antenna PAD for customer's antenna connection. The RF trace in host PCB
connected to the module's RF antenna pad should be coplanar waveguide line or microstrip line,
which characteristic impedance should be close to 50Ω. M12 comes with two grounding pads
which are next to the antenna pad in order to give a better grounding.
Table 24: Pin definition of the RF_ANT
Name Pin
RF_ANT 43
GND 42
GND 44
To minimize the loss on the RF trace and RF cable, they should be designed carefully. It is
recommended that the insertion loss should try to meet the following requirements:

EGSM900<1dB

DCS1800 <1.5dB
M12_Hardware_Design_V3.3
Figure 44: Reference circuit of RF interface
Function
RF antenna pad
Ground
Ground
R1 0R
C1
NM
C2
NM
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