What could be used to send induced/coupled CAN-BUS signal
I've done it (not on CAN) like this: -



The top section shows some data and what you will receive (shown just below) will be a highly differentiated form - just the edge information comes thru - positive edges on the data result in a positive spike and negative data edges result in a negative spike.

Cutting a long story short, you apply upper and lower detection thresholds (a comparator with hysteresis for example but there are other ways) and what the comparator produces is an exact repro of the original data.

Things to watch out for: -


Use a small pick-up loop so that you are not taking significant energy from the signal - the loop I used was about 25mm long by 6 mm wide
Feed it into a low noise fast op-amp circuit - I had a transistor circuit that was phantom powered on mine because it had to sit 10m from the rest of the electronics
Setting the comparator threshold/hysteresis isn't too bad but will take a little bit of setting up - I used a circuit that automatically tracked amplitude and adjusted the thresholds automatically but the "sniffer" I used was sitting in the presence of a large 600 kHz H filed of about 1000 at/m and this had to be contended with.


Mine runs at 80 Mb per second but I think yours will be substantially less so you might need more gain because induction (is better at higher frequencies.