Emc Compliance; Introduction; Emc Regulations For 2.4 Ghz; Etsi En 300-328 Emission Limits For The 2400-2483.5 Mhz Band - Silicon Laboratories BRD4305E Reference Manual

5. EMC Compliance

5.1 Introduction

Compliance of the fundamental and harmonic levels of the BRD4305E Radio Board is tested against the following standards:
• 2.4 GHz:
• ETSI EN 300-328
• FCC 15.247

5.2 EMC Regulations for 2.4 GHz

5.2.1 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.

5.2.2 FCC15.247 Emission Limits for the 2400-2483.5 MHz Band

FCC 15.247 allows conducted output power up to 1 Watt (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.
Additionally, for spurious frequencies above 1 GHz, FCC 15.35 allows duty-cycle relaxation to the regulatory limits. For the EmberZNet
PRO the relaxation is 3.6 dB. Therefore, the -41.2 dBm limit can be modified to -37.6 dBm.
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 -37.6 dBm limit should be applied. For the 4th harmonic the -20 dBc limit should be applied.

5.2.3 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.
Harmonic
2nd
3rd
4th
5th
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Table 5.1. Applied Limits for Spurious Emissions for the 2.4 GHz Band
Frequency
4800~4967 MHz
7200~7450.5 MHz
9600~9934 MHz
12000~12417.5 MHz
BRD4305E Reference Manual
EMC Compliance
Limit
-37.6 dBm
-37.6 dBm
-30 dBm
-37.6 dBm
Rev. 1.0 | 8