Another IEEE Spectrum article describes a medical RFID chip from Verichip; a Spanish subsidiary of Raytheon. A technical description of this new product:
Quote:
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The chip consists primarily of a coil of wire that acts as an antenna and a microchip capable of generating a radio signal that encodes 128 bits of information and is readable from, at most, centimeters away. The reading device emits a magnetic field that oscillates at a frequency of 134 kilohertz. The reader and the chip’s antenna basically form a transformer, turning the oscillating magnetic field into current in the implant.
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Reception range even at 130 kilohertz (below AM or medium wave radio) is 10 cm. Again making it doubtful that TX Tag at 915 Mhz (well above highest TV channel) is RFID. Notice the same power problems that computer chips have as their frequencies approached 1 Ghz. RFID semiconductors have same power loss problems at those frequencies. But RFIDs must be constructed with far less expensive semicondutor technology. Remember, Intel had to push out the envelope to work at such frequencies.
RFID must do so much with so little power. That means operation at lower frequencies. TX Tag sounds more like a battery powered transponder mislabeled by a technically naive reporter.
Demonstrated again is why numbers - the most critical details - are so important in any report.