I mentioned the PHOTOANGLO system (the new version of the radar Appelbaum talked about) has a max 450Mhz bandwidth. At 2W, that’s bleedingly hard to find with conventional TSCM equipment.
To pull it off, I wager you’d need a very, very wideband receiver. One that’s not frequency selective.
I wonder if this would do the job?
Again, by spreading their 2W over 450MHz, the spies make it very hard to detect that you’re being irradiated. Spotting the reflections off the bug becomes, by comparison, almost impossible. But maybe not so impossible to a receiver that can suck up the whole 450MHz at once, if it comes within a few inches of the “implanted device.”