Tektronix 494AP O o a o a A o o o o o o o o o o O o o o o, Span/Dv, MIN RFATTENdB

PerformanceCheckprocedure_ 4g4Al4g4ApServiceVol.1

14.Check FrequencyResponse (Response,about the midpoint between two €xtremes,measuredwith 10dB of RF attenuation and peakingoptimizedin the applicabl€bands for eachcenterfrequencysetting,is as follows:

Band1: +1.5 dB from10 kHzto 1.gGHz

Band2: *2.5 dB from 1.7to S.5GHz

Band3: r2.S dB from 3 to 7.1GHz

Band4: i3.S dB from 5.4 to 1g GHz

Band5: iS.O dB from t5 to 21 GHz)

(Responsewithrespectto 100MHzis as,ollows: Band1: *2.5 dB fromt0 kHzto 1.gGHz Band2: *3.5 dB from t.Z to 5.5GHz

Band3: *3.5 dB from 3 to 7.1GHz

Band4: *4.5 dB from 5.4 to 1gGHz

Band5: *6.5 dB from t5 to 21 GHz)

. The responseat each check point, aboveband l, shouldbe peakedwith the MANUALPEAKcontrot.

^, ?: Check frequency response from 0.01GHz to 21 GHz(Bands1 through5).

(1) Connectthe CAL OUT signatto the RF tNpUT, andperforrnthe <Blue-SHIFT>CALroutine.

(2) Setthe SpectrumAnalyzercontrolsas follows: CENTERFREQUENCY 1OOMHz

SPAN/DV	500kHz
RESOLUTION	3 MHz
REFLEVEL	-20 dBm
VERTICALDTSPLAY	2 dB/Dtv
MIN RFATTENdB	O
TIME/DIV	AUTO
PEAK/AVERAGE	Fully Counterclockwise

(3) Set the CAL AMPL adjustmentfor 5 divisionson the SpectrumAnalyzerdiiptay. This is the 1OOMHz reference. ActivateSAVEA to savethe reference.

(4)Connectth€ test equipmentas shownin Figure 4 - 1 1 .

(5)Set the sweeposcillatorcontrolsfor a cw output that rnatchesthe SAVEA display(outputfrequency of 100MHz and an output amptituOiof approxi- mately-20dBm).

(6)DeactivateSAVEA. Reset the CENTERFRE- QUENCYto 500 MHz, and SpANiDtv to 100MHz, and activateMAXHOLD.

(/)R:seJthe sweep oscillatorcontrolsfor a sweep output from 0.01GHz-1 GHz. Enable singlb sweepon the sweeposcillator.

(8)Check that amplitude deviation from the 100 MHz referencedoes not exceed*2.S dB.

(9)Makea note of the highestand lowestpeaksfor latercomparison.

00)D€activateMAX HOLD, and repeat parts 6 through10 for a CENTERFREQUENCyof 1.5GHz (1 GHzto 1.8GHz).

(11)Calculate the hatfway point between the highestand the lowest peak from the peak data notedin partsg and 10.

(12)Checkthat swept frequencyflatnessis within 11 . 5dB in Band1 .

(13)Switch the Spectrum Analyzer to Band 2 (<Blue-SHIFT>BANDA),CENTERFREeUENCyto

2.7GHz,and SPAN/DIVto 200MHz.

(14)Reset the sweep oscillator controls for a sweep output trom 1.7GHz-3.7 GHz. Enablesin- gle sweepon the sweeposcillator.

Before sweeping any range in Bands 2 through5, set th€ CENTERFREQUENCyto the centerof the range;applya cw signalat this center frequency; and peak the responsewiththe MANUALPEAKcontrol.

(15) Check that amptitude deviation from thE '1

00 MHzreferencedoes not exceedf3.5 dB.

(16)Again,make a note of the highestand lowest peaksfor latercomparison.

(17)- Check frequency response in the range

3.7GHz-5.5 GHz (CENTER FREQUENCY Lt

4.6GHz and SPAN/DV at 200 MHz). Continue makingnotes of the highestand lowest peaksfor comparisonlateron.

(18)Check Bands3 through5 accordingto Tabte

44.8e sure to make a note of the highestand lowest peaksafter each check.

(19)Calculate the halfway point between the highest and the lowest peak from the peak data notedin parts16 and17.

(20)Checkthat swept frequencyflatnessis within

*2.5 dB in Band2 and Band3, within *3.5 dB in Band4, andwithin*5.0 clBin Band5.

lf any segmentor portionof the span fails to meet the specification,set the FRE- QUENCYto the centerof this portion;apply

acw marker at this center frequencyand re-peakwith the MANUALor AUTO PEAK- lNG.Decreasethe FREQUENCYSPAN/DV to displaythat portionand thenrecheckthe frequencyresponsefor this portion.

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