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 thesub-GHz PA it was provided as VBIAS through the discrete balun); for details, see the schematic of the BRD4173A. The transceiverwas operated in continuous carrier transmission mode. The output power of the radio was set to 10 dBm.