Transmitter parameters

AN4271

10/20

DocID024318 Rev 1

2.3

Unwanted emissions in the spurious domain

Spurious emissions are unwanted emissions in the spurious domain at frequencies other

than those of the desired carrier frequency and its sidebands associated with normal test

modulation.

A spectrum analyzer is used as external receiver. The measurement is performed setting

the SPIRIT1 without modulation and observing it at up to 6 GHz as described in the ETSI [

2]

subclause 7.8.

The measurement is split into two graphs: in

Figure 8 the unwanted spurious emission for

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

to a resolution bandwidth of 100 kHz, as required by ETSI [

2]. In Figure 9, the unwanted

spurious emission for frequencies from 1 GHz to 6 GHz is shown. The measurement is

performed setting the instrument to a resolution bandwidth of 1 MHz, as required by ETSI

[

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

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

2] sub-

clause 7.8.

Figure 8. Unwanted spurious emission below 1 GHz

-70

-60

-50

-40

-30

-20

-10

0

10

20

30

0.E+00

1.E+08

2.E+08

3.E+08

4.E+08

5.E+08

6.E+08

7.E+08

8.E+08

9.E+08

1.E+09

Frequency [MHz]

Spirit

ETSI mask

GAMS110320131801FSR