Keysight Technologies E8740A-070, Startup Manual

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Keysight E8740A-070 Start-up Guide 35
6 Next, select the up-converter model. Choose the N9029ACST mixer in the Up
Converter drop down list. Press the Specification button to view some of the
specifications of the N9029ACST.
7 Key in the FMCW radar signal requirements in the FMCW settings box.
For this example, each radar pulse has an increasing linear FM (up chirp)
centered at 79 GHz with a bandwidth of 4 GHz and a sweep time of 4 m s. The
image separation is 4 GHz so that any LO feedthrough and lower image
spectrum is easily filtered by the waveguide filter. Each radar pulse train
constitutes of 4 pulses and a burst period if 24 m s.
To enable a burst train, tick the Enable Burst check box and key in the
parameters in the correct fields.
8 Key in the required amplitude ( 200 mV peak to peak ) in the M8195A AWG
box. In the AWG Waveform Properties box, check the Apply Correction check
box. Press the Preview System Settings button. The dialog box should appear
as in Figure 16 .
9 The Assistant has set the LO source frequency at 37.5 GHz. This will result in a
carrier of 75 GHz since the N9029ACST operates on the x2 harmonic factor of
the LO input frequency. The optimal LO power for the mixer is 5 dBm, the
assistant has set an amplitude of 8 dBm to compensate for the 3 dB loss of the
LO cable.
IQTools will create a FMCW signal with frequency from 2-6 GHz which will be
upconverted by the mixer to 77-81 GHz (upper sideband). The assistant will
always use a fixed sampling frequency of 64 GSa/s.
10 If the user is satisfied with the parameters, press the Generate Waveform
button to create the waveform and download into the M8195A sequence
memory. The sequencer will then be started. The output and marker signal
from the M8195A as captured by a digital oscilloscope is shown in Figure 17 .
During signal generation, the outputs of the Source and M8195A can be
turned on and off and the amplitudes adjusted.
NOTE
Always use the Stop Generation button to stop the sequencer before pressing the
Generate Waveform button again.