RF ID tag reader utilizing a scanning antenna system and method

• US 8,204,438 B2
• Filed: 11/17/2008
• Issued: 06/19/2012
• Est. Priority Date: 03/14/2003
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Paratek Microwave Incorporated (Blackberry Limited)
• Inventors: Patel, Jay, Gupta, Om, Chen, Shuguang, Finn, James S.
• Primary Examiner(s): VO, NGUYEN THANH
• Application Number:
  US12/313,128
• Publication Number:
  US 20090146816A1
• Time in Patent Office: 1,310 Days
• Field of Search: 455/39, 455/41.1, 455/41.2, 455/88, 455/562.1, 342/359, 342/360, 342/361, 342/368, 342/371, 342/372, 342/450, 342/463, 340/10.1, 340/10.42, 340/10.5, 340/10.51, 340/10.52, 340/572.1, 340/572.7
• US Class Current: 455/41.2
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 5/04 Position of source determined by a plurality of spaced direction-finders
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial
• CPC Class Codes: G06K 7/10346 the antenna being of the far field type, e.g. HF types or dipoles
• CPC Class Codes: H01Q 1/42 Housings not intimately mechanically associated with radiating elements, e.g. radome
• CPC Class Codes: H01Q 21/205 providing an omnidirectional coverage turnstile aerials H01Q21/26
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H01Q 3/36 with variable phase-shifters
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40

Abstract

An embodiment of the present invention provides an RF ID card reader, comprising RF ID circuitry to generate an RF ID signal, a transceiver in communication with said RF ID circuitry and an array antenna associated with said transceiver for scanning an area for at least one tag and establishing communication with at least one tag.

Claims

1. An RF ID card reader, comprising:

RF ID circuitry to generate an RF ID signal;

a transceiver in communication with said RF ID circuitry;

a switched polarization antenna associated with said transceiver for communication with at least one tag, wherein the switched polarization antenna provides a plurality of RF signals with at least one vertically polarized RF signal and at least one horizontally polarized RF signal; and

a hybrid coupler connected with the switched polarization antenna via at least one single pole double throw switch, wherein the at least one horizontally polarized RF signal and the at least one vertically polarized RF signal passes through the at least one single pole double throw switch, wherein the at least one single pole double throw switch outputs the at least one horizontally polarized RF signal and the at least one vertically polarized RF signal to the hybrid coupler or passes the at least one horizontally polarized RF signal and the at least one vertically polarized RF signal without converting the polarization, wherein the hybrid coupler converts vertical/horizontal polarizations into two slant polarizations at +45° and

−

45°

.

2. The RF ID card reader of claim 1, wherein said switched polarization antenna is a switched polarization scanning antenna for scanning an area for at least one tag and establishing communication with at least one tag.

3. The RF ID card reader of claim 2, wherein the at least one single pole double throw switch selects the desired set of polarizations for the plurality of RF signals.

4. A method of tracking an object, person or thing, comprising:

associating an RF ID tag with said object, person or thing;

providing an RF ID tag reader with a switched polarization antenna for transmitting information to, and receiving information from, said RF ID tag, said RF ID tag containing information about said object, person or thing, wherein the RF ID tag reader utilizes a hybrid coupler to convert a portion of vertically polarized RF signals and horizontally polarized RF signals to slant polarization signals having slant polarizations at +45° and

−

45°

, wherein a single pole double throw switch selects between bypassing the hybrid coupler to maintain the polarization of the vertically and horizontally polarized RF signals or providing the vertically and horizontally polarized RF signals to the hybrid coupler for conversion to the slant polarization signals.

5. The method of tracking an object, person or thing of claim 4, wherein said switched polarization antenna is a switched polarization scanning antenna for scanning an area for at least one tag and establishing communication with at least one tag.

6. The method of tracking an object, person or thing of claim 4, comprising:

determining a signal strength of communication between the RF ID tag and the RF ID tag reader; and

utilizing the signal strength to adjust position information associated with the object, person or thing.

7. The method of tracking an object, person or thing of claim 4, comprising:

determining time of flight information for RF signals transmitted between the RF ID tag and the RF ID tag reader; and

utilizing the time of flight information to adjust position information associated with the object, person or thing.

8. An RF ID tag system, comprising:

at least one RF ID tag;

at least one RF ID tag reader, said at least one tag reader including at least one RF ID tag reader microcontroller; and

at least one transceiver associated with said at least one microcontroller, said at least one transceiver in communication with a plurality of switched polarization antennas for transmitting signals to and receiving signals from said at least one tag,

wherein the plurality of switched polarization antennas provides a plurality of RF signals with vertically polarized RF signals and horizontally polarized RF signals,

wherein each of the switched polarization antennas is connected with a hybrid coupler via switches, wherein the horizontally polarized RF signals and the vertically polarized RF signals pass through the switches, wherein the switches output the horizontally polarized RF signals and the vertically polarized RF signals to the hybrid coupler or pass the horizontally polarized RF signals and the vertically polarized RF signals without converting the polarization, wherein the hybrid coupler converts vertical/horizontal polarizations into two slant polarizations at +45° and

−

45°

.

9. The RF ID tag system of claim 8, wherein said switched polarization antenna is a switched polarization scanning antenna for scanning an area for at least one tag and establishing communication with at least one tag.

10. The RF ID tag system of claim 8, wherein the switches comprise single pole double throw switches.