5.8 GHz full duplex amplitude shift keying retrodirective interrogator array

Pak Chan, Vincent Fusco

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


This article describes a practical demonstration of a complete full-duplex “amplitude shift keying (ASK)” retrodirective radio frequency identification (RFID) transceiver array.The interrogator incorporates a “retrodirective array (RDA)” with a dual-conversion phase conjugating architecture in order to achieve better performance than is possible with conventional RFID solutions. Here mixers phase conjugate the incoming signal and a carrier recovery circuit recovers incoming angle of arrival phase information of an encoded amplitude shift keyed signal. The resulting interrogator provides a receiver sensitivity level of -109 dBm. A four element square patch RDA gives a 3 dB automatic beam steering angle of acceptance of ±45°. When compared to an RFID system operating by conventional (non-retrodirective) means retrodirective action leads to improved range extension of up to 16 times at ±45°. Operator pointing accuracy requirements are also reduced due to automatic retrodirective self-pointing. These features significantly enhance deployment opportunities requiring long range low equivalent isotropic radiation power (EIRP) and/or RFID tagging of moving platforms.
Original languageEnglish
Pages (from-to)160-164
JournalMicrowave and Optical Technology Letters
Issue number1
Early online date20 Nov 2012
Publication statusPublished - Jan 2013

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Atomic and Molecular Physics, and Optics
  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering


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