U.S. embassy in Moscow
So here is what the U.S. learned from the Russian bombardment of the U.S. embassy with microwaves in Moscow after many years.
By heterodyning two powerful beams of microwaves where one beam mostly cancels out the effect of the other at the location of interest, you will have a near "scalar" radar beam almost undetectable because of the low intensity readings.
The low intensity microwaves still interact with the environment and bounce back to their origination. The original beams were very high intensity. So what this does is creates a method of amplifying the signal to noise ratio. It allows high powered signals to bounce off surfaces with a minimal reaction to objects.
At the receivers, it can then be amplified with a clean signal.
This is the secret to mind reading RADAR.