7. RF Performance
7.1 Conducted Power Measurements
During measurements, the BRD4173A Radio Board was attached to a Wireless Starter Kit Mainboard which was supplied by USB. The
voltage supply for the Radio Board was 3.3 V.
7.1.1 Conducted Measurements in the 434 MHz Band
The BRD4173A Radio Board was connected directly to a Spectrum Analyzer through its SMA connector. The supply for the RF section
(RFVDD) and the sub-GHz power amplifier (SUBGRF_ON, SUBGRF_OP) was 1.8 V provided by the on-chip DCDC converter (for the
sub-GHz PA it was provided as VBIAS through the discrete balun); for details, see the schematic of the BRD4173A. The transceiver
was operated in continuous carrier transmission mode. The output power of the radio was set to 10 dBm.
The typical output spectrum is shown in the following figure.
Figure 7.1. Typical Output Spectrum of the BRD4173A
As shown in the figure, the fundamental is slightly above 10 dBm but still compliant with the 12.1 dBm fundamental limit. The unwanted
emissions are under -60 dBm, so the conducted spectrum is compliant with the regulation limits.
BRD4173A Reference Manual
RF Performance
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