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4-22 Phase Mod - Deviation Accuracy Tests
Performance Verification
4-74
PN: 10370-10386 Rev. B
MG362x1A MM
4-22 Phase Mod - Deviation Accuracy Tests
The Phase Mod - deviation accuracy tests are as follows:
Ext Low Noise ΦM - Phase Deviation Accuracy
FSWP analog demod is used to measure 5 radian phase deviation (at Nmod = 1) at 1 kHz mod rate.
Corresponding FSWP phase deviation uncertainty (spec) is 0.0002*(1+5 rad) = 0.0012 rad = 0.024 %.
Resolution of MG362x1A’s Phase Deviation display is 3 digits. So a readout of 5.00 rad has uniformly
distributed uncertainty of ±0.005 rad and 2
σ
uncertainty of (0.005 rad)*2/sqrt(3) = 0.00577 rad, or 0.115 % of
reading. Combined uncertainty for the Ext LNPM accuracy test is then sqrt(0.024 %^2 + 0.115 %^2) = 0.12 %.
Expected DUT gain drift is negligible, but add about 0.5 % margin. Uncer margin = 0.6 %, which makes
the test limit = ±4.4 % for a ±5 % sales spec.
For the Ext LNPM Input Sensitivity Accuracy test, resolution of the Deviation display is not a factor. Precision
of sensitivity control is < 0.01 %. FSWP demod uncertainty at a mod index of 5 is 0.024 %. DVM accuracy at
100 Hz rate is 0.132 %. Combined measurement uncertainty is sqrt(0.024 %^2 + 0.132 %^2) = 0.134 %. Allow
about 0.9 % margin for DUT variation so that uncer margin = 1.0 %, which makes the test limit = ±4 %
for a ±5 % sales spec.
Ext LNPM accuracy at 1 kHz mod rate is insensitive to variations of YIG tuning sensitivity vs. carrier
frequency. So it is sufficient to test accuracy only at 5 GHz.
Test Setup
Connect equipment as shown in
FSWP:
Tab Analog Demod. If “PM Time Domain” window does not appear, then: Meas Config / Display Config
/ drag “PM Time Domain” to screen center. The “Summary” Display will now show Phase Mod results.
Meas Config / Demod BW = 25 kHz, Meas Time = 350 msec
Scale Config = 2 rad/div.
Demod Config / Demod / AF Coupling = AC, AF HPF = 50 Hz
Trace Config:
Trace 1 Clear/Write, Linear, Smoothing = 1 %.
Trigger button:
Set “PM Offline” as the trigger source.
External Function Generator:
1 kHz, 2 Vpp, Channel ON
External DVM:
RMS AC volts, 1V range
MG362x1A:
Ext Low Noise Phase Mod mode, DC Coupled, Sensitivity = 5 rad/V, Phase Mod ON.
Test Procedure
1.
Wait 2sec for FSWP to complete the RMS Phase Deviation measurement. Note RMS Phase Deviation
(radians) shown in the FSWP “Summary” window. Also note the DVM RMS AC voltage readout.
2.
Calculate Peak Phase Deviation = sqrt(2)*(RMS phase deviation, rad).
3.
Note Phase Deviation indicated by the DUT.
4.
Calculate “Ext LNPM Deviation % Error” = 100*(Calculated Peak Deviation)/(Deviation indicted by
DUT) – 1). Record the result. If result is
≥
–4.4 % and
≤
4.4 %, Record “Pass”, otherwise record “Fail”.
5.
Calculate LNPM Sensitivity = (Calculated Peak Phase Deviation)/(sqrt(2)*(DVM RMS voltage readout)).
6.
Calculate “Ext LNPM Sensitivity % Error” = 100*((Calculated LNPM sensitivity)/(5 rad/V) –1). Record
the result. If the result is
≥
–4 % and
≤
4 %, Record “Pass”, otherwise record “Fail”.
Summary of Contents for Rubidium MG362 1A Series
Page 12: ...Contents 10 PN 10370 10386 Rev B MG362x1A MM ...
Page 16: ...1 9 ESD Requirements General Information 1 4 PN 10370 10386 Rev B MG362x1A MM ...
Page 30: ...2 6 RF Deck Assemblies Functional Description 2 14 PN 10370 10386 Rev B MG362x1A MM ...
Page 66: ...3 11 FM and Phase Modulation Calibration Calibration 3 36 PN 10370 10386 Rev B MG362x1A MM ...
Page 292: ...B 5 Self Test Messages Instrument Messages B 8 PN 10370 10386 Rev B MG362x1A MM ...
Page 293: ......