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azimuth and range in a radar scan
conversion application.
Target Simulator
We can conduct proper functional
test of an Rx through target
simulation using the VSG based on
sync pulses. In this case, the ATE
acts as a target signal generator
coming from the antenna. Each
interrogation is synchronized by a
trigger pulse connected to both the
VSG trigger and the FPGA. Users can
configure the range and azimuth to
simulate with the target. When a
target is ready for simulation, the
VSG generates the reply RF pulses
of a target after the azimuth count
is reached in the FPGA and the
next sync trigger is received from
the radar. The user can select reply
code and mode, and scripted pulses
are generated at the specified range
and azimuth. Targets are simulated
for stationary and trajectory motion.
A user configures moving paths at
different trajectories. The system
can simulate multiple targets at
different ranges and azimuths
from the same VSG. Different
code patterns are applied to the
reply pulses as specified by the
user. Reply pulses are a sequence
of pulses spaced 1 µs apart with a
pulse width of 450 ns. Each target’s
replies are framed with F1 and F2
pulses at the beginning and end
of the sequence. The number of
pulses in a frame is derived by
the mode of interrogation selected
in the GUI. Each sync pulse can
have a different mode of reply
based on the interrogation mode
selected. Such three-reply pulses
are separately configurable and can
be generated through the VSG with
reference to each sync pulse. Figure
5 illustrates reply pulse generation
with range delay, azimuth, and
Figure 5- Pulse Formats
Figure 6- Sequence of Tests
code simulation.
Radar Scan Converter
The system acquires and processes
video signals from the radar in
the TTL format through the FPGA
board. The reply pulses from the
target are demodulated in the
54 l New-Tech Magazine Europe