User manual

PRODUCT OVERVIEW
001-7100-100 Version 0 Page 13 of 66 Vanguard 3G User Manual CDMA Version
2.8.5 Antenna Spacing
Referring to Figure 6 for illustration, Vanguard 3G radiomodem commonly uses four separate
antennas:
•
“T” - Main transceiver -
Constraints are the limit of 20 cm and omni-directional factors
•
“R” - Auxiliary receiver –
Constraints are the receiver spacing of at least 5/8 λ (wavelength) from transceiver antenna and
omni-directional requirements
•
“G” - Global Positioning System (GPS)
Constraints are TX spacing of at least 60cm/23.62 inch from all transmitting antennas and a
clear view of the sky.
•
“W” – WiFi antenna
Constraints are TX spacing of at least 8 inches or 20 cm from all transmitting antennas
Note: For units utilizing diversity cellular antennas, best overall operation is achieved utilizing
antennas with equal gains
WARNING: As per FCC rules, all Vanguard 3G transmitting antennas should be at a minimum of
eight (8) inches (approximately 20 centimeters) from all persons.
T- Primary Antenna
R-Diversity Antenna
W
R
≥23.6"
(
60cm
)
G-GPS Antenna
≥8"
(
20cm
)
G
≥8"
(
20cm
)
W-WiFi Antenna
≥5/8
λ
915 Μ Hz: 8" (20cm)
T
Figure 6 - Antenna Spacing
2
For installation of ground-plane dependent antennas (main cellular and WiFi antennas), the center of
the metal surface used for mounting is preferable for best omni-directional pattern. For ground-
plane independent antennas (diversity and GPS antennas), installation may be close to the edges of
the surface.
For vehicular installations CalAmp recommends the following antenna positions:
2
The diagram is not drawn to scale