Ground Connection; Interference And Sensitivity; Interference From Other Wireless Devices; Host-Generated Rf Interference - Sierra Wireless AirPrime MC7710 Product Technical Specification & Customer Design Manuallines

Rev 6 Mar.13 Proprietary and Confidential - Contents subject to change

Ground connection

When connecting the module to system ground:
• Prevent noise leakage by establishing a very good ground connection to the
module through the host connector.
• Connect to system ground using the two mounting holes at the top of the
module (shown in Figure 5-1 on page
• Minimize ground noise leakage into the RF.
Depending on the host board design, noise could potentially be coupled to
the module from the host board. This is mainly an issue for host designs that
have signals traveling along the length of the module, or circuitry operating at
both ends of the module interconnects.

Interference and sensitivity

Several interference sources can affect the module's RF performance
(RF desense). Common sources include power supply noise and device-
generated RF.
RF desense can be addressed through a combination of mitigation techniques
(Methods to mitigate decreased Rx performance on page
sensitivity measurement
Note: The MC7710 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.
39).
(Radiated sensitivity measurement on page
RF Specifications
42) and radiated
43).
41