Multitech MultiConnect xDot MTXDOT Series, Руководство разработчика

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ANTENNAS
MultiConnect
®
xDot
TM
MTXDOT Developer Guide 29
Chapter 5 – Antennas
Antenna System
The LoRa antenna performance depends on the implementation and antenna design. The integration of the
antenna system into the product is a critical part of the design process; therefore, it is essential to consider it early
so the performance is not compromised. If changes are made to the device's certified antenna system, then
recertification will be required.
This radio transmitter has been tested with both the Pulse and Ethertronics antennas listed below. If you follow
our design guidelines, you do not need to re-certify your design. The antenna you use must maintain the same
specifications. It must be of the same type, with similar in-band and out-of-band radiation patterns. Antennas
having a greater gain than the maximum gain indicated for the listed type, are strictly prohibited for use with this
device.
U.FL and Trace Antenna Options
If using U.FL or trace antennas, note the following:
For a simple trace to RF antennas: Routing must follow standard RF design rules and practices for
stripline/miscrostrip for a 50 ohm impedance line. Use the developer board schematics for a reference
circuit for the a trace antenna.
For U.FL antennas: The antenna and cable combination in your design cannot exceed the performance of
the SMA antenna as listed in the next topic.
The xDot Developer Board includes an Ethertronics M620720 chip antenna, which by default connects the
xDot to the chip antenna. Only one antenna, either U.FL or chip, may be used at a time.
Note: To use the xDot’s U.FL connector, remove resistor C23 and L1, marked on the following image, to
disconnect the chip antenna.
To use the U.FL connector on the xDot, do not connect anything to ANT1 (pin 37) or ANT2 (pin 47).
To design a custom antenna (PCB trace antenna, chip antenna, PCB trace leading to external antenna
connection) do not connect anything to the U.FL connector. Use either ANT1 or ANT2, not both.