Thanks for the interest. I should probably note that while the communication and power harvesting concepts are similar to UHF RFID, the actual operating regime (magnetic coupling) is much more like HF and LF RFID. A UHF RFID apparatus would need to be operating in a completely different regime (electromagnetic coupling between the transmit antenna and robot receive antennas -- where the antennas are generally dipoles or patches).
Because this is magnetic coupling, the "interrogation zone" falls off precipitously with distance from the secondary (resonant) transmit coil. For the system we built, it is likely to be useful only up to ~10 cm (see paper), though this is largely a function of your robots' power consumption and the Q of the transmit coil.
As for charging, the robots are all powered in parallel by the changing magnetic flux through each robot's coil. To prevent interference between robots (and thus allow simultaneous power transfer), the receive coils were intentionally made non-resonant. Again, details are in the paper.
1:43 pm
Hey CT,
Thanks for the interest. I should probably note that while the communication and power harvesting concepts are similar to UHF RFID, the actual operating regime (magnetic coupling) is much more like HF and LF RFID. A UHF RFID apparatus would need to be operating in a completely different regime (electromagnetic coupling between the transmit antenna and robot receive antennas -- where the antennas are generally dipoles or patches).
Because this is magnetic coupling, the "interrogation zone" falls off precipitously with distance from the secondary (resonant) transmit coil. For the system we built, it is likely to be useful only up to ~10 cm (see paper), though this is largely a function of your robots' power consumption and the Q of the transmit coil.
As for charging, the robots are all powered in parallel by the changing magnetic flux through each robot's coil. To prevent interference between robots (and thus allow simultaneous power transfer), the receive coils were intentionally made non-resonant. Again, details are in the paper.