Meaning
Electromagnetic compatibility evaluations verify that multiple co-operating transmitters and receivers can operate simultaneously within a single device housing without causing mutual performance degradation. This co-location testing determines if the internal radios, such as cellular modules and Wi-Fi transceivers, disrupt each other during simultaneous operations. The procedure concludes when all radios meet their receiver sensitivity targets under full transmit load.
Interference Threshold
Transmitting at maximum power can create spurious emissions that fall directly into the receive band of the adjacent radio. These unwanted signals elevate the local noise floor and reduce the overall range of the device. Engineers measure this desensitization using specialized spectrum analyzers and directional couplers to isolate each antenna output.
By identifying the exact frequencies where coupling occurs, developers can implement dynamic frequency allocation or timing-based blanking schemes to share the spectrum efficiently.
Hardware Separation
Physical isolation must be maximized through careful board layout and antenna positioning. Ground plane shielding can block direct radiation paths, and band-stop filters can be integrated to block specific harmonics. These steps are optimized during the layout phase to prevent costly circuit board redesigns.
Certification Signoff
Regulatory bodies require documented proof that the co-located transmitters do not exceed safe human exposure limits or radio emission standards. This testing provides the necessary evidence for fcc and ce submissions. It is the final gate before a wireless product can be legally distributed.