Series 12000A Microwave Synthesizers
4-4
Publication 31231, Rev. J, October 2003
4.2.3
Spurious Signals Tests
4.2.3.1
Description
The output of the 12000A is connected to a spectrum analyzer. Various frequencies are selected and the
analyzer tuned to determine the presence of either harmonically or non-harmonically spurious signals.
4.2.3.2
Equipment Required
UUT
²
Spectrum Analyzer
²
Coaxial Cable
4.2.3.3
Procedure
1.
Connect the equipment as shown in Figure 4-2. Allow the equipment to warm up for at least
30 minutes. Press
[CW]
in the FREQUENCY field on the 12000A and enter the first test data
sheet frequency within the range of the 12000A. The RF amplitude should be at +6 dBm. Press
[RF ON]
to turn on the RF output. Be certain that all modulation is OFF.
2.
Set the spectrum analyzer to view the 12000A output signal. Adjust the analyzer reference
level so that the peak of the displayed signal is at the top graticule line.
3.
Set the spectrum analyzer to maximum span with the signal centered on the screen. Gradually
narrow the span, keeping the signal centered, to observe any spurious signals. Use appropriate
resolution and video bandwidths to allow sufficient dynamic range.
4.
Repeat steps 2 and 3 for the other frequencies on the test data sheet which are within the
operating range of the instrument.
Many spectrum analyzers have a tuned preselector when the frequency is above about 2 GHz. This
reduces the likelihood of analyzer generated spurious signals, but does not eliminate the possibility. If in
doubt, increase the RF attenuation of the analyzer by 10 dB. The signal in question should be reduced by
exactly 10 dB. If not, it is analyzer generated. It is also important for frequencies below the range of the
preselector that sufficient analyzer RF Attenuation be used (typically 30 dB) to avoid the analyzer
generating harmonics of the input signal. The above attenuator shift technique will also allow
verification of harmonic levels.
If a spurious signal appears to be out of specification, first check that the fundamental signal level is at
+6 dBm. Next verify the analyzer accuracy by connecting a known amplitude signal (from the 12000A,
for example) at the spurious frequency.
Figure 4-2: Spurious Signals Tests
Summary of Contents for Series 12000A
Page 3: ...DECLARATION OF CONFORMITY ...
Page 4: ......
Page 11: ...Preface Publication 31231 Rev J October 2003 vii ...
Page 14: ...Series 12000A Microwave Synthesizers x Publication 31231 Rev J October 2003 ...
Page 18: ...Series 12000A Microwave Synthesizers xiv Publication 31231 Rev J October 2003 ...
Page 20: ...Series 12000A Microwave Synthesizers xvi Publication 31231 Rev J October 2003 ...
Page 22: ...Series 12000A Microwave Synthesizers xviii Publication 31231 Rev J October 2003 ...
Page 24: ...Series 12000A Microwave Synthesizers xx Publication 31231 Rev J October 2003 ...
Page 62: ...Series 12000A Microwave Synthesizers 1 38 Publication 31231 Rev J October 2003 ...
Page 234: ...Series 12000A Microwave Synthesizers B 2 Publication 31231 Rev J October 2003 ...
