NORA-W36 series - System integration manual
UBX-22021120 - R01
Module integration
Page 10 of 48
C1-Public
For more information about this and other commands, see also the u-connectXpress AT command
manual
2.3.2
Deep sleep
Deep sleep mode is used to minimize current consumption. In this mode, the UART interface is
disabled, and no Wi-Fi and Bluetooth Low Energy connections are maintained.
The host needs to control when the module should enter and exit Deep sleep mode. After wake up, the
module assumes the same state as it does after a reset.
•
To initiate Deep sleep mode, the host uses the AT command
AT+UPMDS
.
•
To wake up the module from Deep sleep mode, the host sets
GPIO_J9
to GND.
For more information about this and other commands, see also the u-connectXpress AT command
manual
2.4
Antenna integration
Antenna interfaces are different for each module variant in the NORA-W36 series. The modules
support either an internal antenna (NORA-W366) or external antennas connected through a
dedicated antenna pin (NORA-W361).
2.4.1
External antenna interface
The NORA-W361 module is equipped with an antenna signal (
ANT
) pin. The pin has a nominal
characteristic impedance of 50
and must be connected to the antenna through a 50
transmission
line.
Choose an antenna with optimal radiating characteristics for the best electrical performance and
overall module functionality. An internal antenna, integrated on the application board or an external
antenna connected to the application board through a proper 50
connector, can be used.
When using an external antenna, the PCB-to-RF-cable transition must be implemented using either
a suitable 50
connector, or an RF-signal solder pad (including GND) that is optimized for 50
characteristic impedance.
2.4.1.1
Antenna matching
The antenna return loss should be as low as possible across both bands to provide optimal
performance. The enclosure, shields, other components, and surrounding environment might impact
the return loss that is seen at the antenna port. Matching components are often required to retune
the antenna to 50
characteristic impedance.
It is difficult to predict the actual matching values for the antenna in the final form factor. Therefore,
it is good
practice to have a placeholder in the circuit with a “pi” network, with two shunt components
and a series component in the middle. This allows maximum flexibility while tuning the matching to
the antenna feed.
2.4.1.2
Approved antenna designs
NORA-W361 modules come with a pre-certified design that utilizes a U.FL connector for an external
antenna. The certification can be used to save costs and time during the certification process. See
also
The designer integrating a u-blox reference design into an end-product is solely responsible for any
unintentional RF emission generated by the end product.
