4-14 FM Flatness Tests
Performance Verification
4-40
PN: 10370-10386 Rev. B
MG362x1A MM
Test Procedure
1.
Wait approximately 1 second for the FSWP to complete an RMS FM Deviation measurement.
2.
Read “FM RMS Deviation” from the “Summary” window.
3.
Calculate: FM Deviation = sqrt(2)*(RMS FM Deviation). Record the result. It should be close to 1.28 kHz.
4-14 FM Flatness Tests
The FM flatness tests are as follows:
FM Highpass Filter 3 dB BW
Connect equipment as shown in
Test Setup
FSWP:
Tab “Analog Demod”. This will close out the previous measurement mode, activate Analog Demod, and
open the “FM Time Domain” and “Summary” windows.
Meas Config:
Demod BW = 40 MHz, Meas Time = 100 msec.
Scale Config:
2 MHz/div.
Trace Config:
Trace 1 Clear/Write, Linear, Smoothing = 2 %.
Trigger button:
Set “FM Offline” as the trigger source.
External Function Generator:
1 kHz, 2Vpp, Channel ON.
MG362x1A:
FM OFF, Low Noise FM mode, Ext FM, DC Coupled, Sensitivity = 5 MHz/V, FM ON.
Test Procedure
1.
Wait 500 msec for FSWP to complete a measurement cycle. Note RMS FM deviation indicated in the
FSWP “Result Summary” window.
2.
In MG362x1A’s FM controls, change from “DC Coupled” to “1 kHz HPF”.
3.
Wait 500 msec for FSWP to complete a measurement cycle. Note FM deviation indicated in the FSWP
“Result Summary” window.
4.
Calculate HPF rolloff, dB = 20*log((FM dev from
)/(FM dev from
)). Record this result for the
1 kHz HPF. Result should be close to 3 dB.
5.
Set external function generator frequency to 62 Hz.
6.
In MG362x1A’s FM controls, change from “1 kHz HPF” to “62Hz HPF”.
7.
Wait 500 msec for FSWP to complete a measurement cycle. Note RMS FM deviation indicated in the
FSWP “Result Summary” window.
8.
Calculate HPF rolloff, dB = 20*log((FM dev from
). Record this result for the
62Hz HPF. Result should be close to 3 dB.
Ext Low Noise FM Flatness and 3 dB BW
This procedure verifies (low noise mode) FM flatness at mod rates up to 1 MHz and 3 dB BW at mod rates up to
10 MHz. FM flatness is tested at 2.6, 5, 10, and 20 GHz carrier frequencies as a sampling across the YIG
oscillator 2-20 GHz tuning range, and at modulation multiplication ratio, Nmod, = 1. This sampling also
represents FM flatness for carrier frequencies < 2 GHz or > 20 GHz, due to frequency division or
multiplication, i.e. Nmod
≠
1. (See chart in section B1 to see how Nmod varies with carrier frequency).
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: ......