I'm having trouble understanding how RFID works on the technical side. I know an RF signal is sent to an antenna, modulated, and then backscattered back to the RFID reader. For example, Does this ON-OFF Keying system work?
My logic is as follows: Then antenna receives the RF Signal.
The signal is absorbed through ground when the transistor is on and "acting" like a closed switch. This represents a zero.
When the transistor is off, it acts like an open circuit and reflects the RF Signal back to the antenna and the antenna radiates back to the reader. This represents a one.
What I see wrong with this is that the antenna cannot simultaneously transmit and receive the RF signal, or at least to my knowledge it can't.
Another example is this google image I found. How does the antenna receive, modulate, and send back a signal simultaneously. Are there two antennas that are "lumped" as one antenna?