Instruction Manual

6. EMC Compliance
6.1 Introduction
BRD4186C Radio Board fundamental and harmonic levels compliance is tested against the following standards:
• 2.4 GHz:
• ETSI EN 300-328
• FCC 15.247
6.2 EMC Regulations for 2.4 GHz
6.2.1 ETSI EN 300-328 Emission Limits for the 2400-2483.5 MHz Band
Based on ETSI EN 300-328, the allowed maximum fundamental power for the 2400-2483.5 MHz band is 20 dBm EIRP. For the unwan-
ted emissions in the 1 GHz to 12.75 GHz domain, the specific limit is -30 dBm EIRP.
6.2.2 FCC15.247 Emission Limits for the 2400-2483.5 MHz Band
FCC 15.247 allows conducted output power up to 1 W (30 dBm) in the 2400-2483.5 MHz band. For spurious emissions, the limit is
-20 dBc based on either conducted or radiated measurement, if the emission is not in a restricted band. The restricted bands are speci-
fied in FCC 15.205. In these bands, the spurious emission levels must meet the levels set out in FCC 15.209. In the range from
960 MHz to the frequency of the 5th harmonic, it is defined as 0.5 mV/m at 3 m distance, which equals to -41.2 dBm in EIRP.
If operating in the 2400-2483.5 MHz band, the 2nd, 3rd, and 5th harmonics can fall into restricted bands. As a result, for those harmon-
ics the -41.2 dBm limit should be applied. For the 4th harmonic, the -20 dBc limit should be applied.
6.2.3 Applied Emission Limits for the 2.4 GHz Band
The above ETSI limits are applied both for conducted and radiated measurements.
The FCC restricted band limits are radiated limits only. In addition, Silicon Labs applies the same restrictions to the conducted spec-
trum. By doing so, compliance with the radiated limits can be estimated based on the conducted measurement by assuming the use of
an antenna with 0 dB gain at the fundamental and the harmonic frequencies.
The overall applied limits are shown in the table below. For the harmonics that fall into the FCC restricted bands, the FCC 15.209 limit
is applied. ETSI EN 300-328 limit is applied for the rest.
Table 6.1. Applied Limits for Spurious Emissions for the 2.4 GHz Band
Harmonic Frequency Limit
2nd 4800~4967 MHz -41.2 dBm
3rd 7200~7450.5 MHz -41.2 dBm
4th 9600~9934 MHz -30.0 dBm
5th 12000~12417.5 MHz -41.2 dBm
BRD4186C Reference Manual
EMC Compliance
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