Ceyear 4051 Series, Руководство пользователя

Страница: 678 / 751

8. Specifications and test methods
8.5 Performance characteristics test
664
8.5.1.2 Tests of amplitude accuracy and range
8.5.1.2.1 Amplitude range
a) Test items
It is used to check the range of amplitude from the maximum signal to the minimum signal of the 4051
analyzer. The maximum signal of the 4051 analyzer has the highest level.
For the safety input level, the minimum signal is the display average noise level.
b) Test procedure
1) The maximum signal LMAX (maximum safety input level) is tested based on Section 8.5.1.2.2.
2) The minimum signal LDNAL (display average noise level) is tested based on Section 8.5.1.3.2.
3) Calculate the amplitude measurement range according to the formula (15) with the measured display
average noise level of each band of the signal/spectrum analyzer. If requirements in 1) and 2) are met, the
amplitude range will be noted as ―compliant‖, otherwise it will be considered as noncompliant.
4) Reset the 4051 analyzer and select internal 500 MHz input interface. Set the center frequency as 500 MHz,
the frequency span as 1 kHz, the resolution bandwidth as 100 Hz, the input attenuator as 10 dB and the
reference level as -15 dBm.
5) Execute Peak Search and Marker Delta.
6) Set the input attenuator as 0dB, 2dB, 4dB, 6dB, 8dB, 20dB, 30dB, 40dB, 50dB, 60dB and 70dB
respectively
（
The maximum setting of 4051L attenuator is 60dB
）
. If the instrument can properly
indicate the decrement, note ―compliant‖ in the 4051 Record Sheet, otherwise as ―noncompliant‖.
8.5.1.2.2 Maximum safety input level
a) Test items
The maximum safety input level refers to the maximum level allowed at the input interface of the
signal/spectrum analyzer that will not damaged the instrument.
Damages of the signal/spectrum analyzer can be checked and the maximum safety input level can be
determined whether to meet relevant requirements by producing a signal consistent to the maximum safety
input level and inputting it into the signal/spectrum analyzer.
Since the test has high risk, several frequency points can be selected to test according to the following
procedure if the purchase has such need.
b) Test equipment
Synthesized signal generator (E8257D/1464 is recommended)
38701D/80244 is recommended for the high power amplifier.
U2000B is recommended for the USB power meter.
c) Test steps
1) Set the signal output of the signal generator as off, the frequency as 3GHz, amplitude as -50 dB and power
step as 0.1 dB.
2) Reset 4051 and set its center frequency as 3 GHz, the frequency span as 2 MHz and the reference level as
+30 dBm.
3) Connect the test equipment according to solid lines of Fig. 8.8 with the output cable of the high power
amplifier connected to the USB power meter sensor rather than the signal/spectrum analyzer.