[miekw]

Here's the paper: https://homes.cs.washington.edu/~gshyam/Papers/loRaBackscatt...

Tech like this already exists (look up "UHF RFID") and the picture they've got looks very similar to existing tags (image search for "alien rfid tag").

The interesting thing here is managing to implement LoRa's modulation scheme in a passive tag.

[junkcollector]

It's not a passive tag. If you only read 3 sentences into the abstract, you find out that it is an active device. This is repeated at the end of the abstract and right at the beginning of page 2 in the introduction.