Com-Power CDN-AF4, Руководство пользователя

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Model CDN -AF4
4.1 Setting Levels
After you make all the connection shown in figure 2-5, you are
now ready for level measurements . The open circuit voltage
levels given in table 2-2 must be recalculated to to account for
the 50
Ω
impedance adapter and the spectrum analyzer in the
test setup. They are given below:
Level 1 0.167 RMS 150 kHz - 80 MHz
Level 2 0.5 RMS 150 kHz - 80 MHz
Level 3 1.67 RMS 150 kHz - 80 MHz
The above voltage levels were calculated by deviding the open
circuit voltage specified in table 2-1 by a factor of 6. The factor
of 6 established due to the following. When the 150
Ω
impedance adapter is connected CDN EUT port, the voltage
level at the output terminal of the 150
Ω
adapter it will be to half
the injected voltage level at the CDN input. When adapter output
is connected to a 50
Ω
spectrum analyzer, the voltage measured
will be one third of the that value.
Next, turn on the power amplifier and signal generator and take
the measurements from 150 kHz - 80 MHz for each level with
CW unmodulated. The rate of the sweep shall not exceed 1.5 x
10
3 decades/seconds. If the frequency is swept incrementally,
the step size shall not exceed 1% start and thereafter 1% of
preceding frequency value. Create a chart and record the
frequency and input power needed at each frequency to achieve
each of the three levels for the entire range. (This process can
be automated with appropriate software, contact Com-Power
for details.)
The next step is to activate the 1 kHz sine wave modulator on
your signal generator set it to 80% modulation depth and repeat
measurements described in the previous paragraph .
4.2 Expected amplifier power requirement
The power requirement to generate the maximum level is not
expected to be more than 10 Watts. This takes into account
attenuation factor 9 -12 dB of the CDN for entire frequency
range and the loss of amplifier forward power due to 3:1 VSWR
created by the CDN and the passive impedance adapter.
2-5