Channel Power (Bluetooth Spectrum)
The trace shows the measured power in each channel of the Bluetooth radio channel grid — one value per channel, integrated from the Spectrum over the full width of the channel. For LE that width is 2 MHz Megahertz: A unit of frequency equal to one million hertz or cycles per second. across a 40-channel grid whose channel k is centered at 2402 + 2k MHz.
Each point is plotted against its channel's absolute center frequency, so this trace can be overlaid directly on the spectrum and on the Band Power trace. Channels that the acquisition span did not cover are not plotted, and read out as under a marker.
Setting Power Calculation to reports each channel as a mean power spectral density (dBm deciBels referenced to a milliWatt: dB relative to 1 milliwatt dissipated in the nominal input impedance of the analyzer/Hz) instead of an integrated power (dBm).
For LE in-band emissions this trace is not the quantity the limits are applied to. The specification states the test over 1 MHz measurement bands, so the limit test, the mask and the pass/fail verdict all run on the band grid — see Band Power and Band Table. A 2 MHz channel collects two 1 MHz bands, so no limit line is drawn on this trace for LE; comparing a band limit against a channel power would report a failure that the specification does not call one.
The worst-offending band and the overall pass/fail result are reported in the Summary trace.
See Also
