Keysight E8357D/67D & E8663D PSG User’s Guide 109
Basic Digital Operation
Using the Dual ARB Waveform Player
Adding Real–Time Noise to a Dual ARB Waveform (E8267D with
Option 403)
The signal generator with option 403 can apply AWGN (additive white
gaussian noise) to a carrier in real time while the modulating waveform file is
being played by the Dual ARB waveform player. The AWGN can be configured
using front panel softkeys. The
Carrier to Noise Ratio
softkey allows you to
specify the amount of noise power relative to carrier power that is applied to
the signal. The
Carrier Band wid th
softkey sets the bandwidth over which the
noise is integrated and the
Noise Band wid th Factor
softkey allows you to
select a flat noise bandwidth. The
Output Mux
softkey enables diagnostic
control of additive noise, so that only the noise, only the carrier, or the sum of
both the noise and the carrier are output from the internal baseband generator.
With the ALC off, this feature enables direct measurement of the carrier or the
noise contributions independently from the total power. The system still
behaves as if both the noise and the carrier are present on the output when it
comes to determining the Auto Modulation Attenuation and the RMS level for
RMS Power Search.
These softkeys are described in the
Keysight PSG Signal Generators Key
Reference
.
The following procedure sets up a carrier and modulates it using the
pre–defined SINE_TEST_WFM waveform file. AWGN is then applied to the
carrier.
Configuring AWGN
1.
Preset the signal generator. Press the
Preset
hardkey.
2.
Press the
Frequency
hardkey and enter 15 GHz.
3.
Press the
Amplitude
hardkey and enter –10 dBm.
4.
Press
RF On Off
to
On
.
5.
Press
Mode
>
Dual ARB
>
Select Waveform
and select the
SINE_TEST_WFM waveform.
6.
Press
Select Waveform
.
7.
Press
ARB Off On
to
On
.
8.
Press
ARB Setup
>
ARB Sample Clock
enter 50 MHz.
9.
Press
Real–time Noise Setup
>
Carrier to Noise Ratio
and enter 30 dB.
10.
Press
Carrier Band wid th
and enter 40 MHz.
11.
Press
Real–time Noise Off On
to
On
.
This procedure applies AWGN to the 15 GHz carrier. The displayed power level
of the signal generator, –10 dBm, will include the noise power which is set as a
carrier to noise ratio (C/N) of 30 dB. Noise power, for the purpose of C/N, is
