User's Manual

GSM/GPRS Module Series
M85 Hardware Design
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4 Antenna Interface
The Pin 63 is the RF antenna pad. The RF interface has an impedance of 50Ω.
Table 24: Pin Definition of the RF_ANT
4.1. Reference Design
The external antenna must be matched properly to achieve best performance, so the matching circuit is
necessary, the reference design for RF is shown as below.
Module
RF_ANT
0R
NM NM
Figure 46: Reference Design for RF
Pin Name
Pin No.
Description
GND
61
Ground
GND
62
Ground
RF_ANT
63
RF antenna pad
GND
64
Ground
GND
65
Ground
GND
66
Ground