Netgear NM7371 用户手册
Rev 3 Sep.13
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The severity of this interference depends on the closeness of the other antennas to the
module’s antenna. To determine suitable locations for each wireless device’s antenna,
thoroughly evaluate your host device’s design.
module’s antenna. To determine suitable locations for each wireless device’s antenna,
thoroughly evaluate your host device’s design.
Host-generated RF interference
All electronic computing devices generate RF interference that can negatively affect the
receive sensitivity of the module.
receive sensitivity of the module.
Proximity of host electronics to the antenna in wireless devices can contribute to
decreased Rx performance. Components that are most likely to cause this include:
decreased Rx performance. Components that are most likely to cause this include:
•
Microprocessor and memory
•
Display panel and display drivers
•
Switching-mode power supplies
Methods to mitigate decreased Rx performance
It is important to investigate sources of localized interference early in the design cycle.
To reduce the effect of device-generated RF on Rx performance:
To reduce the effect of device-generated RF on Rx performance:
•
Put the antenna as far as possible from sources of interference. The drawback is
that the module may be less convenient to use.
that the module may be less convenient to use.
•
Shield the host device. The module itself is well shielded to avoid external inter-
ference. However, the antenna cannot be shielded for obvious reasons. In most
instances, it is necessary to employ shielding on the components of the host device
(such as the main processor and parallel bus) that have the highest RF emissions.
ference. However, the antenna cannot be shielded for obvious reasons. In most
instances, it is necessary to employ shielding on the components of the host device
(such as the main processor and parallel bus) that have the highest RF emissions.
•
Filter out unwanted high-order harmonic energy by using discrete filtering on low
frequency lines.
frequency lines.
•
Form shielding layers around high-speed clock traces by using multi-layer PCBs.
•
Route antenna cables away from noise sources.
Radiated Spurious Emissions (RSE)
When designing an antenna for use with NETGEAR embedded modules, the host device
with a NETGEAR embedded module must satisfy the radiated spurious emissions (RSE)
test cases described in 3GPP2 (CDMA) and 3GPP (LTE).
with a NETGEAR embedded module must satisfy the radiated spurious emissions (RSE)
test cases described in 3GPP2 (CDMA) and 3GPP (LTE).
Note that antenna impedance affects radiated emissions, which must be compared
against the conducted 50-ohm emissions baseline. (NETGEAR embedded modules meet
the 50-ohm conducted emissions requirement.)
against the conducted 50-ohm emissions baseline. (NETGEAR embedded modules meet
the 50-ohm conducted emissions requirement.)