AN4117

Transmitter parameters

Doc ID 023222 Rev 1

9/22

Figure 6.

Adjacent power measurement, 25 kHz narrowband channel spacing,

4.8 Kbps data rate, 2.4 kHz frequency deviation, GFSK (BT=0.5)

modulation

2.2

Modulation bandwidth

The range of the modulation bandwidth includes all associated side-bands above the

appropriate emissions level and the frequency error or drift under extreme test conditions.

The frequency drift in extreme test conditions primarily depends on the crystal quality, which

is not included in this report.

Figure 7 illustrates the ETSI spectral mask with which the radio must comply at the sub-

band edges. Basically, there are only two limit thresholds; what changes is the bandwidth of

integration at the different offset regions.

The same spectral masks are reported in Figure 8, 9, 10, 11 and 12. In Figure 8 the data

rate is set to 1.2 Kbps, the frequency deviation is set to 1 kHz and the modulation is set to 2-

FSK (GFSK). In Figure 9 the data rate is set to 2.4 Kbps, the frequency deviation is set to

2.4 kHz and the modulation is set to Gaussian FSK (GFSK) with a BT = 0.5. In Figure 10 the

data rate is set to 4.8 Kbps, the frequency deviation is set to 2.4 kHz and the modulation is

set to Gaussian FSK (GFSK) with a BT = 0.5. In Figure 11 the data rate is set to 38.4 Kbps,

the frequency deviation is set to 20 kHz and the modulation is set to Gaussian FSK (GFSK)

with a BT = 1. In Figure 12 the data rate is set to 250 Kbps, the frequency deviation is set to

127 kHz and the modulation is set to Gaussian FSK (GFSK) with a BT = 1. The applied

output power is set to 11 dBm.

With these parameters, the spectral masks of SPIRIT1 comply with ETSI [2] subclause 7.7.