RF Antenna Guidance
The antenna gain shall be < 5 dB for an ideal 0 dBi radiator. If using an antenna other than the
Swarm Coiled ¼ wave antenna, please refer to the notes below:
● An antenna that has a gain of > 5dB will not be compliant with current certifications.
● The end-user will have to get a Supplier’s Declaration of Conformity (SDoC) and use
Swarm’s FCC/IC ID as included.
● If the antenna being used has > 2dBi of gain, then the antenna will have to be evaluated
for SAR.
GPS Antenna Guidance
A GPS antenna is
required for operation
. Any passive GPS antenna with an appropriate
connection to the Modem’s U.FL male connector or via the GPS_OUT pin is acceptable for use.
One such example of a passive antenna is:
[Molex Part Number 1461860300]
.
Active GPS antennas are supported at
3.3V
and up to
35mA
. Any active antennas that require
a different voltage or maximum current must be powered by the user’s host device.
Example u.fl to SMA cable
Example u.fl to u.fl cable
6.2.2 Ground Plane Requirements
An antenna counterpoise or antenna ground plane is required for the Swarm Coiled ¼ Wave
Antenna. Ground planes are electrically conductive surfaces that are connected to the ground
conductor of the antenna that serve as a reflecting surface for radio waves.
To date, Swarm has reliably communicated with its satellites using a coiled ¼-wave antenna
with a 50 cm long, 20 AWG (0.812mm diameter) wire descending from the ground of the SMA
connector of the antenna mount. Swarm has also reliably communicated with its satellites using
a solar panel off to one side as the ground plane of sufficient size: 30cm x 30cm x 0.3cm
Integrated solutions are recommended to be designed with the use of a symmetrical ground
plane or similar RF grounding solution for the best results with a Swarm-provided antenna.
© 2022 SWARM TECHNOLOGIES
SWARM M138 MODEM PRODUCT MANUAL · REV 1.20 · FEBRUARY 2022
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