Millimetre-wave image-based chipless RFID system

Patent metadata

Field	Value
Publication number	US-9904824-B2
Application number	US-201615331140-A
Country	US
Kind code	B2
Filing date	Oct 21, 2016
Priority date	Oct 23, 2015
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

A mm-wave RFID tag interrogation apparatus includes multiple transmitting antennas, and multiple receiving antennas. The transmitting and receiving antennas are spatially distributed and oriented in orthogonal polarization states. A transmitter is coupled to the transmitting antennas, and transmits a corresponding multiple number of separable mm-wave signals. A receiver coupled to the receiving antennas is configured to extract separable components of received mm-wave signals. A processing unit processes the extracted signal components using a synthetic aperture algorithm. An RFID tag, readable by the interrogation apparatus, includes meander-line conductive elements arranged to encode information spatially on a substrate.

First claim

What is claimed:

1. A mm-wave RFID tag interrogation apparatus comprising:
a plurality (P) of transmitting antennas having a first spatial distribution and each arranged to transmit mm-wave radiation having a first state of polarisation;
a plurality (Q) of receiving antennas having a second spatial distribution and each arranged to receive mm-wave radiation having a second state of polarisation which is substantially orthogonal to the first state of polarisation;
at least one transmitter coupled to the transmitting antennas and configured to transmit a corresponding plurality of separable mm-wave signals;
at least one receiver coupled to the receiving antennas and configured to extract separable signal components of corresponding mm-wave signals received via each one of the receiving antennas; and
a processing unit arranged to receive and process the extracted signal components using a synthetic aperture algorithm so as to locate one or more spatially distributed remote cross-polarising reflecting elements;
wherein the apparatus utilizes a multiple-input multiple-output (MIMO) combination between the plurality of transmitting antennas and the plurality of receiving antennas, and wherein the synthetic aperture algorithm and MIMO combination emulate a larger aperture size than an actual aperture size of the plurality of transmitting antennas and the plurality of receiving antennas.

2. The apparatus of claim 1 wherein the transmitter is configured to transmit the plurality of separable signals which comprises a set of pulses wherein each pulse is transmitted successively in time via a corresponding one of the transmitting antennas.

3. The apparatus of claim 2 wherein the receiver is configured to extract received signal components by gating output from each one of the receiving antennas during a period corresponding to reception of one of the set of transmitted pulses.

4. The apparatus of claim 1 wherein the synthetic aperture algorithm generates a virtual antenna array having a larger number of antenna elements and a larger aperture size than the real antenna array comprising the transmitting and receiving antennas.

5. The apparatus of claim 1 wherein the transmitting antennas and receiving antennas are arranged in corresponding parallel linear arrays.

6. An RFID system comprising an interrogation apparatus according to claim 1 , wherein the one or more spatially distributed remote cross-polarising reflective elements each comprises a conductive meander-line element.

7. The system of claim 6 wherein the conductive meander-line elements are arranged in a two-dimensional array comprising a first plurality (n) of columns and a second plurality (m) of rows, wherein each column encodes an information bit.

8. A method of mm-wave RFID tag interrogation comprising:
transmitting, via a plurality (P) of transmitting antennas having a first spatial distribution, a corresponding plurality of separable mm-wave signals;
receiving, via a plurality (Q) of receiving antennas having a second spatial distribution, a corresponding plurality of received mm-wave signals;
processing the received millimeter wave signals to extract separable signal components of each received mm-wave signal; and
further processing the extracted signal components using a synthetic aperture algorithm so as to locate one or more spatially distributed remote cross-polarising reflective elements;
wherein the apparatus utilizes a multiple-input multiple-output (MIMO) combination between the plurality of transmitting antennas and the plurality of receiving antennas, and wherein the synthetic aperture algorithm and MIMO combination emulate a larger aperture size than an actual aperture size of the plurality of transmitting antennas and the plurality of receiving antennas.

9. A mm-wave RFID tag which comprises an arrangement of conductive elements configured to encode information spatially on a substrate, wherein each conductive element is adapted to scatter incident-polarised mm-wave radiation to produce a substantially orthogonally polarised reflected mm-wave radiation, and wherein each conductive element comprises a meander-line, wherein the mm-wave RFID tag is configured to be interrogated by the interrogation apparatus of claim 1 .

10. The mm-wave RFID tag of claim 9 wherein the arrangement comprises a two-dimensional array comprising a first plurality (n) of columns and a second plurality (m) of rows, wherein each column encodes an information bit.

11. The mm-wave RFID tag of claim 10 wherein a first binary value is encoded by the presence of the conductive elements in a corresponding column, and a second binary value is encoded by the absence of the conductive elements in a corresponding column.

Assignees

• Univ Monash

Inventors

• Karmakar Nemai Chandra
• Zomorrodi Mohammad

Classifications

• G06K7/10356 Primary

  using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas · CPC title

• H01Q1/00

  Details of, or arrangements associated with, antennas (arrangements for varying orientation of directional pattern H01Q3/00) · CPC title

• H04B7/00

  Radio transmission systems, i.e. using radiation field (H04B10/00, H04B15/00 take precedence) · CPC title

• G06K7/10366

  the interrogation device being adapted for miscellaneous applications · CPC title

• G06K19/0672

  with resonating marks · CPC title