User's Manual

page 43/51
HiAll
NC
User Manual 2012/06/28
8. RADIO INTEGRATION
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Radio engineering skills are mandatory to get accurate radio performance on customer’s product
8.1 GSM antenna connection
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RF lines shall match 50 ohms impedance
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In order to achieve optimum sensitivity and output power in radiated mode, it is strongly recommended to
implement a matching circuit, as shown on schematic below
Figure 28: GSM antenna connection schematic
More information about GSM radio design can be found in [3].
8.2 GNSS antenna connection
8.2.1 Reference schematics
HiAll
NC
module supports both passive and active antenna.
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HiAll
NC
embeds a high performance SAW filter. No external filtering is required.
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Typical schematic for passive antenna is similar to GSM antenna schematic above.
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If active antenna use, HiAll
NC
module can be configure to output a GPS_LNA_EN signal, allowing
disabling the external LDO when GNSS receiver is in stand-by or shut-down mode.
Enabling GPS_LNA_EN is performed through AT+GNSSRUN command
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If active antenna connection, a power supply shall be connected to the GNSS feed point, according to
schematic example below: