Ceyear 4051 Series, Руководство пользователя

Страница: 697 / 751

8. Specifications and test methods
8.5 Performance characteristics test
683
IF2 image response
10) Set the frequency of the synthesized signal generator as 1 GHz, the power as -4 dBm, the center frequency
of the 4051 analyzer as 1 GHz and the test frequency of the power meter as 1 GHz.
11) Execute Peak Search and Marker Delta.
12) Set the frequency of the synthesized signal generator and the power meter as the frequencies to enable IF2
image response as listed in the 4051 Record Sheet.
13) Adjust the output amplitude of the synthesized signal generator until the the power meter reading is
closest to -10 dBm.
14) Record the Marker Delta amplitude value in the 4051 Record Sheet.
15) Set the 4051 analyzer, the synthesized signal generator and the power meter according to frequencies
listed in the 4051 Record Sheet and repeat step 11 ~ 14.
IF1 image response
16) Set the frequency of the synthesized signal generator as 1 GHz, the power as -4 dBm, the center frequency
of the 4051 analyzer as 1 GHz and the test frequency of the power meter as 1 GHz.
17) Execute Peak Search and Marker Delta.
18) Set the frequency of the synthesized signal generator and the power meter as the frequencies to enable IF1
image response as listed in the 4051 Record Sheet.
19) Adjust the output amplitude of the synthesized signal generator until the the power meter reading is
closest to -10 dBm.
20) Record the Marker Delta amplitude value in the 4051 Record Sheet.
21) Set the 4051 analyzer, the synthesized signal generator and the power meter according to frequencies
listed in the 4051 Record Sheet and repeat step 17 ~ 21.
8.5.1.3.5 Second harmonic distortion
a) Test items
When a signal is input to nonlinear devices (such as mixer and amplifier), such nonlinear devices will
generate subharmonic for such input signal. The unwanted second harmonic component added to the signal is
called second harmonic distortion. The value of the second harmonic distortion can be obtained by inputting
sine wave signals as pure as possible (by connecting the external filter) into the signal/spectrum analyzer and
testing the second harmonic component caused after such signal passes the signal/spectrum analyzer.
b) Testing block diagram and testing instrument and equipment
Synthesized signal generator (E8257D/1464 is recommended)
500 MHz low-pass filter: 1
1.6GHz low-pass filter: 1
4GHz low-pass filter: 1
26.5GHz low-pass filter: 1
c) Test steps
Second harmonic distortion (10 MHz ~ 0.6 GHz)
1) Connect the 500 MHz low-pass filter and the BNC cable to the instrument as shown in Fig. 8.15. Reset
the 4051 analyzer to provide frequency reference for the synthesized signal generator.