Interference From Other Wireless Devices; Host-Generated Rf Interference; Device-Generated Rf Interference - Sierra Wireless AirPrime MC7455 Hardware Integration Manual

Hardware Integration Guide
14 Proprietary and Confidential - Contents subject to change
RF desense can be addressed through a combination of mitigation techniques
(Methods to Mitigate Decreased Rx Performance on page
sensitivity measurement
Note: The MC7455 is based on ZIF (Zero Intermediate Frequency) technologies. When
performing EMC (Electromagnetic Compatibility) tests, there are no IF (Intermediate
Frequency) components from the module to consider.

Interference From Other Wireless Devices

Wireless devices operating inside the host device can cause interference that
affects the module.
To determine the most suitable locations for antennas on your host device,
evaluate each wireless device's radio system, considering the following:
• Any harmonics, sub-harmonics, or cross-products of signals generated by
wireless devices that fall in the module's Rx range may cause spurious
response, resulting in decreased Rx performance.
• The Tx power and corresponding broadband noise of other wireless devices
may overload or increase the noise floor of the module's receiver, resulting in
Rx desense.
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.

Host-generated RF Interference

All electronic computing devices generate RF interference that can negatively
affect the 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:
• Microprocessor and memory
• Display panel and display drivers
• Switching-mode power supplies

Device-generated RF Interference

The module can cause interference with other devices. Wireless devices such as
AirPrime embedded modules transmit in bursts (pulse transients) for set durations
(RF burst frequencies). Hearing aids and speakers convert these burst
frequencies into audible frequencies, resulting in audible noise.
(Radiated Sensitivity Measurement on page
15) and radiated
15).
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