Anritsu Rubidium MG362 1A Series, Руководство по обслуживанию

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Performance Verification 4-14 FM Flatness Tests
MG362x1A MM PN: 10370-10386 Rev. B 4-43
5. Note “PM RMS Deviation” shown in the FSWP “Summary” window. Units should be radians.
6. Calculate “FM pk dev” = sqrt(2)*(mod rate)*(RMS phase deviation, radians)
7. Calculate: "Norm FM dev" = (FM pk dev)/(FM pk dev at 1 kHz mod rate for the current RF freq)
8. At 1 kHz mod rate, this gives “Norm FM dev” = 1. Other mod rates may produce a different result.
9. Calculate: Flatness = 20*log(Norm FM dev). Record Flatness for the current mod rate.
10. Refer to Table 4-6 to find the test limits associated with the current mod rate.
11. If mod rate is ≤ 1 MHz:
12. If (Flatness > "1 dB Test Limit", or Flatness < “-1 dB Test Limit”), then report "Flatness Fail" and PLL
lock status for the current mod rate.
13. If mod rate is > 1 MHz:
14. If (Flatness > "3 dB Test Limit", or Flatness < “–3 dB Test Limit”), then report "3 dB BW Fail" and PLL
lock status for the current mod rate.
15. If mod rate < 10 MHz, set Func Generator frequency = next mod rate from Table 4-6 . Wait 30 msec. Go to
Step 4 .
16. If RF frequency < 20 GHz and mod rate = 10 MHz, set FM OFF, set DUT and FSWP to next RF
frequency, wait 30 msec, go to
Step 2 .
17. If RF frequency = 20 GHz and mod rate = 10 MHz:
18. If no Flatness Fails have occurred for any of the tested combinations of RF frequency and mod rate
≤ 1 MHz, report Pass for the Ext LNFM Flatness test.
19. If no 3 dB BW Fails have occurred for any of the tested combinations of RF frequency and mod rate > 1
MHz, report Pass for the Ext LNFM 3 dB BW test.
20. Exit.
Int Low Noise FM Flatness and 3 dB BW
Test method and Test limit derivation are essentially identical to those for the “Ext Low Noise FM Flatness
and 3 dB BW” test. But the Internal FM test does not use an external function generator to source the
modulating waveform, so the waveform generator’s flatness spec is not included in test limit calculations. The
resulting test limits (see
Table 4-7 ) turn out a bit more generous than for the Ext FM case. As was done for the
Ext FM case, 1 % margin (0.086 dB) is included for DUT variation. As before, FSWP uncertainty contribution
to the test limits is close to negligible.
Measurement Uncertainties and Test Limits Table for the Int Low Noise FM Flatness test is shown
Table 4-7 .
Table 4-7.
Int Low Noise FM Flatness Test
mod rate
Hz
mod
index at
2 MHz pk
dev FSWP
phase
demod
unc, % FSWP
unc vs.
1kHz,
dB FSWP
unc vs.
1kHz
dB func
gen flat
vs.1kHz
dB
total
unc
dB
1dB
test
limit,
dB –1dB
test
limit,
dB 3dB
test
limit,
dB
–3dB test
limit, dB
1.00E+03 2.00E+03 0.02 0 0 0 n/a n/a 1.00E+03
3.00E+03 6.67E+02 0.02 0.002 0 0.00 0.91 –0.91 3.00E+03
1.00E+04 2.00E+02 0.02 0.002 0 0.00 0.91 –0.91 1.00E+04
3.00E+04 6.67E+01 0.02 0.002 0 0.00 0.91 –0.91 3.00E+04
5.00E+04 4.00E+01 0.02 0.002 0 0.00 0.91 –0.91 5.00E+04
7.00E+04 2.86E+01 0.02 0.003 0 0.00 0.91 –0.91 7.00E+04