SARA-G450 - System integration manual
UBX-18046432 - R08 Product testing Page 126 of 143
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5.2.1 “Go/No go” tests for integrated devices
A “Go/No go” test is performed to compare the signal quality with a “Golden Device” in a position with
excellent network coverage and known signal quality. This test should be performed after the
call/data connection has been established. AT+CSQ is the typical AT command used to check signal
quality in term of Received Signal Strength Indication (RSSI). See the u-blox AT commands
manual [11] for the +CSQ AT command syntax description and usage.
☞ These kinds of test may be useful as a “go/no go” test but not for RF performance measurements.
This test is suitable to check the communication with the host controller or SIM card, the audio and
the power supply functionality. It is also a mean to verify if components at the antenna interface are
well-soldered.
5.2.2 Functional tests providing RF operation
An overall RF functional test of the device including the antenna can be performed with basic
instruments such as a spectrum analyzer (or an RF power meter) and a signal generator using
dedicated commands over the FT UART interface.
In this way, the module can be set to Rx and Tx test modes ignoring 2G signaling protocol. The module
can be set:
In transmitting mode in a specified channel and power level in all 2G bands
In receiving mode in a specified channel to return the measured power level in all 2G bands
⚠ To avoid module damage during the transmitter test, an antenna that meets the module
specifications or a 50 Ω termination must be connected to the ANT pin.
⚠ To avoid module damage during the receiver test, the maximum power level received at the ANT
pin must meet the module specifications.
☞ A functional test using dedicated commands over the FT UART interface causes the module to
emit RF power ignoring the 2G signaling protocol. This emission can generate interference that
can be prohibited by law in some countries. The use of this feature is intended for testing purposes
in controlled environments by qualified users and must not be used during normal module
operation. u-blox assumes no responsibilities for the inappropriate use of this feature.