DocID024733 Rev 1

9/20

AN4305

Transmitter parameters

20

B = A + 10 log (BWref/BWmeasured)

where:

–

B is the value referred to the reference bandwidth

–

A is the value at the narrower measurement bandwidth

The measured value A must be used directly if the measured spectrum is a discrete spectral

line. A discrete spectrum line is defined as a narrow peak with a level of at least 6 dB above

the average level inside the measurement bandwidth.

For measurements above 1 GHz, the peak value shall be measured, the “max hold” function

of the spectrum analyzer shall be used. In this case the reference bandwidth for the

measurement receiver must be 1 MHz.

The measurement is split into six figures: in Figure 7 the unwanted spurious emission for

frequencies below 1 GHz is shown. The measurement is performed setting the instrument

to max hold with a resolution bandwidth of 10 kHz. In Figure 8 the unwanted spurious

emission for frequencies from 1 GHz to 4 GHz is shown. The measurement is performed

setting the instrument to max hold with a resolution bandwidth of 1 MHz, as required by

ETSI [2.]. In the two graphs, the mask requirement from ETSI is reported also.

The spurious emissions near the modulated signals are also investigated. In Figure 9 and

10 the spurious emissions with a span of 200 kHz for the two different cases are shown. The

channel used, and its adjacent and alternate channels are not considered, as described in

the ETSI [2.] subclause 7.8. In Figure 11 and 12, the spurious emissions with a span of 800

kHz for the two different cases are shown. The channel used, and its adjacent and alternate

channels are also not considered.

The unwanted emissions in the spurious domain of the SPIRIT1 complies with ETSI [2.]

sub-clause 7.8.

Figure 7. Unwanted emission in the spurious domain mask below 1 GHz

AM17218v1

-70

-60

-50

-40

-30

-20

-10

0

10

20

30

0.0E+00

2.0E+08

4.0E+08

6.0E+08

8.0E+08

1.0E+09

Frequency [Hz]

Spirit

ETSI mask