RCM Compliance for End-products Using Compliant Integrated Cellular Modules

The response to this question is “No” the radiated spurious emissions (RSE) results are not likely to be the same when a cellular module is integrated into an end-product host device with a higher gain antenna compared to the antenna used during standalone testing. There are various factors that influence RSE measurements in an integrated product.

Antenna gain, for example. If the end-product is using a higher gain antenna than that used when the module was tested can increase the strength of both the desired signal and any spurious emissions. This can lead to higher levels of radiated spurious emissions being detected.

Another factor to consider is antenna pattern and orientation. The radiation pattern of the antenna can change, affecting the direction and magnitude of emissions. This may lead to different measurement results compared to the standalone module results.

Physical placement of the antenna and/or module and the construction of the enclosure can also have an impact. The physical environment, including the placement of the antenna and the materials used in the host device, can affect the propagation of electromagnetic waves. Metallic enclosures or other components can cause reflections, shielding, or absorption, altering the emission characteristics.

Electromagnetic interference from other electronic components contained in the host device can interact with the cellular module, potentially creating additional spurious emissions or affecting the measurement.

Differences in grounding and the circuit layout between the standalone module test configuration compared to the integrated product configuration can affect electromagnetic compatibility (EMC) and emissions characteristics.

Because of these factors, it is necessary to re-test the ETSI EN 301 908-1 radiated spurious emission within the context of the final end-product to ensure compliance with AS/CA S042. This testing will capture the impact of possible higher gain antenna and other changes introduced by the integration.

For more information on this topic, please contact Tony Stefanovski at Comtest Group on
+061 (0) 3 9645 5933 or email us comtest@comtest.com.au.