7.1.2 Conducted Measurements in the 2.4 GHz Band
The BRD4257A Radio Board was connected directly to a Spectrum Analyzer through its UFL connector (the R1 resistor was removed
and a 0 Ohm resistor was soldered to the R2 resistor position). The supply for the RF section (RFVDD) was 1.8 V provided by the on-
chip DCDC converter, the supply for the 2.4 GHz power amplifier (PAVDD) was 3.3 V provided by the mainboard; for details, see the
schematic of the BRD4257A. The transceiver was operated in continuous carrier transmission mode. The output power of the radio was
set to 19 dBm.
The typical output spectrum is shown in the following figure.
Figure 7.2. Typical Output Spectrum of the BRD4257A
As shown in the figure, the fundamental is slightly lower than 19 dBm and all of the unwanted emissions are under the -37.6 dBm ap-
plied limit.
Note:
The conducted measurement is performed by connecting the on-board UFL connector to a Spectrum Analyzer through an SMA
Conversion Adapter (P/N: HRMJ-U.FLP(40)). This connection itself introduces approximately 0.3 dB insertion loss.
BRD4257A Reference Manual
RF Performance
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