u-blox SARA-G3 Series, Руководство по системной интеграции

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SARA-G3 series - System Integration Manual
UBX-13000995 - R06 Objective Specification System description
Page 43 of 218
1.7 Antenna interface
1.7.1 Antenna RF interface (ANT)
The ANT pin of SARA-G3 modules represents the RF input/output for transmission and reception of the
GSM/GPRS RF signal. The ANT pin has a nominal characteristic impedance of 50  and must be
connected to the antenna through a 50  transmission line to allow proper RF transmission and reception
in operating bands.
1.7.1.1 Antenna RF interface requirements
Table 8Table 8 summarizes the requirements for the antenna RF interface ( ANT ). Refer to section 2.3.1
for suggestions to properly design an antenna circuit compliant to these requirements.
The antenna circuit affects the RF compliance of the device integrating SARA-G3 series module with
applicable required certification schemes. Compliance is guaranteed if the antenna RF interface (ANT)
requirements summarized in
Table 8Table 8 are fulfilled.
Item Requirements Remarks
Impedance 50  nominal characteristic impedance The impedance of the antenna RF connection must
match the 50
 impedance of the ANT pin.
Frequency Range SARA-G350, SARA-G310:

824..960 MHz (GSM 850, GSM 900)

1710..1990 MHz (GSM 1800, GSM
1900)
SARA-G300:

880..960 MHz (GSM 900)

1710..1880 MHz (GSM 1800)
The required frequency range of the antenna depends
on the operating bands of the used SARA-G3 module
and the used Mobile Network.
V.S.W.R
Return Loss
< 2:1 recommended, < 3:1 acceptable
S
11
< -10 dB recommended, S
11
< -6 dB
acceptable
The impedance of the antenna termination must match
as much as possible the 50  impedance of the ANT
pin over the operating frequency range.
Input Power > 2 W peak The antenna termination must withstand the maximum
peak of power transmitted by SARA-G3 modules during
a GSM single-slot call.
Gain
See section 4.2.2 for gain limits The antenna gain must not exceed the herein specified
value to comply with FCC radiation exposure limits.
Detection Application board with antenna detection circuit If antenna detection is required by the custom
application, proper antenna detection circuit must be
implemented on the application board as described in
section 2.3.2.
Antenna assembly with built-in diagnostic circuit If antenna detection is required by the custom
application, the external antenna assembly must be
provided with proper diagnostic circuit as described in
section 2.3.2.
Table 8: Summary of antenna RF interface (ANT) requirements