Meaning
CE Mode B is a specific operational state used during radio testing to govern how a wireless connectivity module manages duty cycles and spurious emissions under ETSI EN 300 328 standards. Radio compliance engineers apply CE Mode B to force a transceiver into continuous modulated transmission without frequency hopping, which allows spectrum analyzers to capture peak power output and occupied bandwidth accurately. This testing protocol stops applying once the device transitions from initial regulatory type approval into normal multi-channel packet transmission.
Thermal Throttling
Continuous transmission under CE Mode B drives internal junction temperatures up rapidly because power amplifiers run without typical idle gaps. Hardware integration teams mount the module against an aluminium housing plate with thermal interface pads to absorb this sustained heat load during the compliance sweep. Thermal dissipation limits dictate the maximum duration of the test sweep before solder joint stress compromises the assembly.
Power Calibration
Battery-powered smart devices often lack the DC power supply stability required for compliant RF measurements during unpulsed output. Test houses connect a calibrated bench source directly to the module power pads to prevent voltage droop from skewing the modulation spectrum. Voltage regulation tolerances at this stage determine whether the device passes spurious domain emissions limits or fails due to sideband splatter.
Antenna Handover
Integrated patch antennas behave differently inside a sealed plastic enclosure compared to an open bench test fixture. Component suppliers measure antenna return loss separately from the final assembly, but the notified body evaluates the whole product with the CE Mode B profile active. Radiated spurious emissions testing captures both module output and enclosure leakage in a single sweep.
