Instruction Manual

7.2.1 Maximum Radiated Power Measurements
For the transmitter antenna, the on-board printed inverted-F antenna of the BRD4186C Radio Board was used (the R1 resistor was
mounted). The supply for the RF section (RFVDD) and the 2.4 GHz power amplifier (PAVDD) was 1.8 V provided by the on-chip DC-
DC converter; for details, see the BRD4186C schematic. The transceiver was operated in unmodulated carrier transmission mode. The
output power of the radio was set to 10 dBm based on the conducted measurement.
The results are shown in the tables below. The correction factors are applied based on the BLE 125 Kb/s coded modulation, shown in
section 7.1.2 Conducted Power Measurements with Modulated Carrier. For the rest of the supported modulation schemes, the
correction factors are larger, thus the related calculated margins would be higher compared to the ones shown in the table below. Thus,
the margins below can be considered as worst case margins.
Table 7.2. Maximums of the Measured Radiated Powers in EIRP [dBm] and the Calculated Modulated Margins in [dB] with the
Wireless Starter Kit Mainboard; PAVDD = 1.8 V
Frequency
(2440 MHz)
Measured Un-
modulated EIRP
[dBm]
Orientation
BLE 125 Kb/s Coded Modulation
Limit in EIRP
[dBm]
Correction Fac-
tor [dB]
Calculated
Modulated EIRP
[dBm]
Modulated Mar-
gin [dB]
Fund 13.4 XZ/H NA (0 is used) 13.4 16.6 30.0
2nd -56.9 XZ/H -2.7 -59.6 18.3 -41.2
3rd -41.5 YZ/H -4.8 -46.3 5.1 -41.2
4th <-50* -/- -5.5 <-50 >20.0 -30.0
5th -50.1 YZ/H -6.3 -56.4 15.2 -41.2
* Signal level is below the Spectrum Analyzer noise floor.
As shown in the table, with 10 dBm output power, the radiated power of the fundamental is higher than 10 dBm due to the high antenna
gain. The 3rd harmonic is very close to the limit with the Wireless Starter Kit Mainboard in case of the unmodulated carrier transmis-
sion. But with the relaxation of the supported modulation schemes, the margin is at least 5.1 dB.
7.2.2 Antenna Pattern Measurements
The measured normalized antenna patterns are shown in the following figures.
0°
45°
90°
135°
180°
225°
270°
315°
-35
-30
-25
-20
-15
-10
-5
0
Normalized Radiation Pattern [dB], BRD4186C
with WSTK, XY cut
Horizontal
Vertical
0° at X axis
0°
45°
90°
135°
180°
225°
270°
315°
-35
-30
-25
-20
-15
-10
-5
0
Normalized Radiation Pattern [dB], BRD4186C
with WSTK, XZ cut
Horizontal
Vertical
0° at Z axis
0°
45°
90°
135°
180°
225°
270°
315°
-35
-30
-25
-20
-15
-10
-5
0
Normalized Radiation Pattern [dB], BRD4186C
with WSTK, YZ cut
Horizontal
Vertical
0° at Z axis
Figure 7.3. Normalized Antenna Pattern of the BRD4186C with the Wireless Starter Kit Mainboard
BRD4186C Reference Manual
RF Performance
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