DocID025421 Rev 1

7/19

AN4378

Transmitter parameter

19

3

Transmitter parameter

All the measurements reported here are measured using the following parameters:

Tc = 25 °C, Vdd = 3.3 V, f = 2402 MHz (lower frequency of the useful bandwidth), unless

otherwise specified.

3.1

6 dB channel bandwidth

The 6 dB channel bandwidth is defined as the difference between the upper and lower

frequencies that are -6 dB relative to the peak.

The measurements are performed in conducted mode, connecting the BlueNRG application

board to a spectrum analyzer. The RBW (resolution bandwidth) of the spectrum must be set

to about 1-5% or the BlueNRG bandwidth, not to exceed 100 kHz. The VBW (video

bandwidth) must be equal to or greater than 3 times the RBW. The detector must be set to

peak, the trace to max hold, and the span set wide enough to capture the entire modulation

envelope.

The 6 dB bandwidth measurement is shown in Figure 4. The measured bandwidth is more

than 730 kHz.

Figure 4. 6 dB bandwidth measurement

AM17619v1

-30

-25

-20

-15

-10

-5

0

5

10

2.4010E+09

2.4012E+09

2.4014E+09

2.4016E+09

2.4018E+09

2.4020E+09

2.4022E+09

2.4024E+09

2.4026E+09

2.4028E+09

2.4030E+09

Frequency [Hz]

6 dB

730 kHz