UM-B-074
DA1468x Range Extender Daughterboard
User Manual
Revision 1.1
17-Apr-2018
CFR0012
52 of 60
© 2018 Dialog Semiconductor
15.2.4
Emission Limitations Radiated (Transmitter)
15.2.4.1
Test Specification
Radiated emissions which fall in restricted bands, as defined in FCC 15.205 must also comply with
the radiated emission limits specified in FCC 15.209. See
Figure 40
.
Figure 40: FCC Radiated Emission Limits
The emission limits shown in the table above are based on measurements employing a CISPR
quasi
–peak-detector, except for frequency bands 9 kHz to 90 kHz, 110 kHz to 490 kHz and above
1000 MHz. Radiated emission limits in these three bands are based on measurements employing an
average detector.
For average radiated emission measurements above 1000 MHz, there is also a limit corresponding
to 20 dB above the specified values, which applies when measuring with a peak detector function.
15.2.4.2
Test Setup
The measurement was performed in a conducted way, using the measurement settings for the
radiated test. These results may differ from the radiated ones.
Only the emissions for the frequency range of 2.31 GHz to 2.39 GHz (Restricted Band A) and
2483.5 GHz to 2.5 GHz (Restricted Band B) were measured.
The DA14680/681 range extender was mounted on a PRO-motherboard. In order to evaluate the
emissions in the restricted bands for the upper and lower channel, the
SDK RF_Tools_CLI
was used.
The boards under test were set into continuous wave modulation transmit mode using the command:
ble_txstream \<FREQUENCY_MHz\> \<POWER\> \<PAYLOAD_TYPE\>
.
An RF cable assembly was connected to the J3 RF Switch connector (MM8130-2600 by Murata) and
at the other end to the spectrum analyzer. Three channels were tested: channels 0, 19 and 39.
15.2.4.3
Test Results
Lower Restricted Area of 2.31 GHz to 2.39 GHz (RA)
Both peak and RMS values are more than 16 dB below the limit.
Upper Restricted Area of 2.4835 GHz to 2.5 GHz (RB)
Both peak and RMS values are below the limit. Peak values have a worst case margin of more than
10 dBm while RMS has a margin of more than 1 dBm from the limit. See
Table 27
.
Only the channels closest to the Restricted Areas are shown in the plots, because the present the
highest emission values.
