7.2 Radiated Power Measurements
During measurements the BRD4154A 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. The radiated power was measured in an antenna chamber by rotating the DUT in 360
degree with horizontal and vertical reference antenna polarizations in the XY, XZ and YZ cuts. The measurement axes are as shown in
the figure below.
Figure 7.2. DUT: Radio Board with the Wireless Starter Kit Mainboard (Illustration)
Note:
The radiated measurement results presented in this document were recorded in an unlicensed antenna chamber. Also the radi-
ated power levels may change depending on the actual application (PCB size, used antenna etc.) therefore the absolute levels and
margins of the final application is recommended to be verified in a licensed EMC testhouse!
7.2.1 Radiated Measurements in the 2.4 GHz band
For the transmitter antenna the on-board printed Inverted-F antenna of the BRD4154A board was used (the R1 resistor (0 Ohm) was
mounted). The supply for the radio (RFVDD) was 1.8 V provided by the on-chip DC-DC converter, the supply for the power amplifier
(PAVDD) was 3.3 V provided by the Motherboard (for details, see the schematic of the BRD4154A). The transceiver was operated in
continuous carrier transmission mode. The output power of the radio was set to 19.5 dBm.
The results are shown in the table below.
Table 7.1. Maximums of the Measured Radiated Powers of BRD4154A
2.4 GHz
EIRP [dBm]
Orientation
Margin [dB]
Limit in EIRP [dBm]
Fund
21.9
XZ/H
8.8
30
2nd
-42.9
XZ/H
5.3
-37.6
3rd
-56.0
YZ/H
18.4
-37.6
4th
-50.7
YZ/V
20.7
-30
5th
Noise
*
-/-
>10
-37.6
* Signal level is below the Spectrum Analyzer noise floor.
As it can be observed, thanks to the high gain of the Inverted-F antenna, the level of the fundamental is higher than 19.5 dBm. The
strongest harmonic is the double-frequency one but its level is only -42.9 dBm which is under the -37.6 dBm applied limit by approx. 5
dB.
BRD4154A Reference Manual
RF Performance
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