UHF RFID Readers
4.1 A Radio’s Days (And Nights)
An RFID reader is, at heart, a radio transceiver: a transmitter and receiver that work together to communicate with the tag. As such, it faces the same challenges all radios encounter, plus a few specialized problems unusual in wireless communications but well-known to practitioners of that other passive communications technology, radar.
Every radio transmitter must deliver:
• Accuracy: the transmitter must accurately modulate the carrier frequency with the desired baseband signal, and maintain the carrier at the desired frequency.
• Efficiency: the transmitter must deliver this undistorted signal at the desired absolute output power without wasting too much DC power. The final amplifier ...