u-blox SARA-G3 Series User Manual

SARA-G3 series - System Integration Manual
UBX-13000995 - R06 Objective Specification Design-in
Page 120 of 218
2.3.2.1 Guidelines for ANT_DET layout design
Figure 42Figure 42 describes the recommended layout for the antenna detection circuit to be provided on
the application board to achieve antenna detection functionality, implementing the recommended schematic
described in Figure 41Figure 41 and Table 22Table 22.
SARA-G350
C2
R1
D1
C1
L1
J1
Figure 42: Suggested layout for antenna detection circuit on application board
The antenna detection circuit layout suggested in Figure 42Figure 42 is here explained:
 The ANT pin is connected to the antenna connector by means of a 50  transmission line,
implementing the design guidelines described in section 2.3.1 and the recommendations of the SMA
connector manufacturer
 DC blocking capacitor at the ANT pin (C2) is placed in series to the 50  transmission line
 The ANT_DET pin is connected to the 50  transmission line by means of a sense line
 Choke inductor in series at the ANT_DET pin (L1) is placed so that one pad is on the 50 
transmission line and the other pad represents the start of the sense line to the ANT_DET pin
 The additional components (R1, C1 and D1) on the ANT_DET line are placed as ESD protection

u-blox SARA-G3 Series Specifications

General

Brand	u-blox
Model	SARA-G3 Series
Category	GSM/GPRS Modules
Language	English