Jungik Suh from Keysight recently took us through a simulation of an automotive radar system, a hot topic these days thanks to work being done in autonomous vehicles.
The point of simulating a radar signal is to provide a test signal for downstream electronics that will act on what shows up in the radar return. The Keysight simulation was able to generate multiple targets, traveling at different velocities, weather conditions, and so on. This simulated data can be downloaded into hardware under design. Then it can be compared to real testing results. If something is wrong, developers can immediately fix whatever is causing the difference between the ideal simulated situation versus the test result.
The simulated radar waveform comes from an arbitrary waveform generator. It goes to an up-converter which converts it to a 79 GHz signal. Suh says the same configuration can be used to generate 24 and 77 GHz signals for other radar bands. In the demo, the up-converted signal got beamed to another horn antenna through the air, at which point it went to a down-converter and then to an oscilloscope for the further analysis.