126
Chapter 4
Performance Tests
4. Displayed Average Noise Level
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4. Displayed Average Noise Level
Description
The displayed average noise level is checked at three frequencies with an LO power level of
+15.2 dBm. The RF source is turned off and, at each frequency, the conversion loss
measured in the Conversion Loss Test is entered into the spectrum analyzer. The spectrum
analyzer is put in zero span and the average noise level is measured. The displayed
average noise level is measured at the lowest and highest frequency in the band, as well as
the frequency at which the mixer has the maximum conversion loss.
Procedure
1. Connect an SMA cable from the 1ST LO OUTPUT of the spectrum analyzer to the
INPUT of the 11975A Amplifier. Connect a second SMA cable to the OUTPUT of the
amplifier.
2. Connect the 8481A Power Sensor to the 436A Power Meter sensor cable, then zero and
calibrate the 436A Power Meter.
3. Set the spectrum analyzer controls as follows:
SHIFT
⇑
⇑
⇑
⇑
(selects U Band)
FREQUENCY SPAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 Hz
CENTER FREQUENCY (sets the LO frequency to 5.0 GHz) . . . . . . 50.3 GHz
CAUTION
When you are using an 11975 Amplifier with an 11974, you must set the
amplifier rear-panel ALC switch to ON before you connect the amplifier to the
test setup. If the ALC switch is left in the OFF position, the amplifier output
power is high enough to destroy the mixer diodes.
4. On the 11975A Amplifier, set the rear-panel ALC switch to ON, then connect the 8481A
Power Sensor to the free end of the cable installed on the OUTPUT connector of the
amplifier. Set the 436A Power Meter Cal Factor % to the appropriate value for a
frequency of 5 GHz.
5. Adjust the amplifier OUTPUT POWER LEVEL for a reading of +15.2 dBm
±
0.1 dBm on
the power meter.
6. Connect the equipment as shown in
on page 106. Turn off the 8349B
Amplifier and the RF power on the synthesized sweeper. They will remain off for this
entire test.
Summary of Contents for 11974 Series
Page 5: ...4 ...
Page 8: ...7 General Information 1 General Information ...
Page 28: ...27 Installation 2 Installation ...
Page 47: ...46 Chapter2 Installation Returning Equipment for Service Installation ...
Page 48: ...47 Operation 3 Operation ...
Page 97: ...96 Chapter3 Operation Using 8561A 62A 62B Spectrum Analyzers Operation ...
Page 98: ...97 Performance Tests 4 Performance Tests ...
Page 148: ...147 Safety and Regulatory Information 5 Safety and Regulatory Information ...