Campbell CELL200 Series Product Manual page 33

FIGURE 6-4. Antenna connections
1. Connect the cellular antenna to the Primary Antenna connector. Mount the cellular
antenna so there is at least 20 cm between the antenna and the user or any bystander.
2. Connect a second antenna, if used, to the Diversity Antenna connector.
Antenna diversity, also called space diversity, is a scheme that uses two or more antennas to
improve the quality and reliability of a wireless link. Often, especially in urban and indoor
environments, there is no clear line of sight between transmitter and receiver. Instead, the signal
is reflected along multiple paths before finally being received. Each bounce can introduce phase
shifts, time delays, attenuations, and distortions that can destructively interfere with one another
at the aperture of the receiving antenna. Diversity-antenna-capable devices support multiple
antennas (usually two) in order to combat this phenomenon and minimize its effects.
Diversity antennas are not required for 2G/3G connections; however, they are highly
recommended in order to get the most reliable connection, especially in areas of low coverage.
Identical or very similar antennas should also be used for the best results.
For 4G networks, the second antenna operates as a MIMO (multiple input, multiple output )
antenna, providing a second receive path. This connection is required for operation on 4G/LTE
networks.
CELL200-Series 4G LTE Cellular Module 29