ANTENNAS
18
Dragonfly
TM
MTQ-LSP3-B03 Device Guide
Antenna diversity provides an advantage in complex environments because if one receive antenna has a poor
signal due to an interference null pattern, the other antenna is likely not in the null and has better reception. The
radio compares the reception from both receive antennas and uses the one with the strongest signal.
Antenna diversity is unnecessary when the device has an unobstructed signal path from the cell tower, such as in a
flat area away from buildings. In good reception environments, the product application might prohibit using two
receive antennas.
Placing External Antennas
Antennas are usually a quarter wavelength apart from each other. With multiband radios where the quarter
wavelengths in each band are diverse from each other, this rule may not be practical. Choose spacing based on the
band used most often or the band with connection difficulty. Some environments are harsher on particular bands.
Multi-Tech products have antenna connectors at the best spacing for the product size.
Placing antennas in close proximity to each other is not optimal, but you can do it if necessary. It depends on the
signal strength to and from each antenna.
Placing GPS Antennas
GPS antennas need access to the sky. Position the GPS antenna so the diversity antennas do not block its access to
the sky.
Selecting Antennas
Select an antenna based on your product and application. Typically, both antennas are the same because either
can be the main receive antenna. However, if the antenna connectors are too close together, use a similar antenna
on a short cable for the second receive only antenna.
Antenna Approvals and Safety Considerations
Note the following:
PTCRB and the carriers conduct antenna diversity tests.
There are no EMC concerns about antenna diversity.
All antennas need to have a minimum flammability rating.
Safety requirements depend on your final product.
Antennas are not approved for outdoor use. Do not extend antennas outside of any building.
Diversity and Power Draw
There are no significant power draw differences.
Important
: You must deploy with two antennas, unless your carrier has authorized you to deploy with one
antenna.
OEM Integration
FCC & IC Information to Consumers
The user manual for the consumer must contain the statements required by the following FCC and IC regulations:
47 C.F.R. 15.19(a)(3), 15.21, 15.105 and RSS-Gen Issue 3, Dec 2010; 7.1.2 and 7.1.3
