6.2.1 Antenna Characteristics
The Modem is certified with the following antenna as described below. No power reduction
compensation is required for use with this antenna.
Swarm Coiled ¼ Wave Antenna
Parameter
Value
Length
22.0 cm
Diameter (Connector)
11.2 mm
Diameter (along major length)
7.6 mm
Weight
31.5 g
Operating Temperature
-55 °C to +130 °C
Operating Humidity
0-100% humidity, condensable
Impedance
50 Ohms nominal
Polarization
Linearly Polarized
VSWR (between Swarm Bands)
Max Δ < 0.5
Gain
2.0 dBi
Frequency
137.000-138.000 MHz (Rx)
148.000-150.000 MHz (Tx)
Connector
SMA male (U.FL to SMA female cable
required)
Antenna Ground Plane
Required
, see
Antenna Height Requirement
1m above the ground/solid surfaces
Antenna Classification
Mobile, Fixed
Minimum separation distance from body
36 cm
Table 14:
Antenna characteristics for Swarm Coiled ¼ Wave Antenna.
© 2022 SWARM TECHNOLOGIES
SWARM M138 MODEM PRODUCT MANUAL · REV 1.20 · FEBRUARY 2022
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