Method for isolating radio propagation zones

• US 7,369,051 B1
• Filed: 11/09/2007
• Issued: 05/06/2008
• Est. Priority Date: 11/09/2007
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: De Gennaro, Steven V., Duri, Sastry S., Moskowitz, Paul A.
• Primary Examiner(s): Bugg; George
• Assistant Examiner(s): Walk; Samuel J.
• Application Number:
  US11/937,979
• Time in Patent Office: 179 Days
• Field of Search: 340/10.1, 340/572.1, 343/838, 343/841, 700/214, 700/215, 700/217
• US Class Current: 340/572.1
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10316 using at least one antenna particularly designed for interrogating the wireless record carriers antennas in general H01Q1/22

Abstract

A method for using a radio frequency identification (RFID) system including a transponder, an antenna, and a reader, the antenna coupled to the reader, the antenna and the reader for transmitting a radio signal to the transponder and for receiving a response radio signal from the transponder, the response radio signal including data from the transponder, the method including: selecting a curtain that limits propagation of the radio signal; and placing the curtain in an area through which the radio signal would otherwise propagate; wherein the curtain includes a plurality of flexible strips transparent to visible light, the long edge of each of the strips is oriented in substantially the vertical direction, more than one strip overlaps a portion of the width of an adjacent strip along the length of the adjacent strip, and the length of each of the strips is substantially greater than the width of each of the strips.

Claims

1. A method for using a radio frequency identification (RFID) system comprising a transponder, an antenna, and a reader, the antenna coupled to the reader, the antenna and the reader for transmitting a radio signal to the transponder and for receiving a response radio signal from the transponder, the response radio signal comprising data from the transponder, the method comprising:

selecting a curtain that limits propagation of the radio signal; and

placing the curtain in an area through which the radio signal would otherwise propagate;

wherein the curtain comprises a plurality of flexible strips transparent to visible light, the long edge of each of the strips is oriented in substantially the vertical direction, more than one strip overlaps a portion of the width of an adjacent strip along the length of the adjacent strip, and the length of each of the strips is substantially greater than the width of each of the strips.

2. The method as in claim 1, wherein the curtain is associated with a portal through which a person, a vehicle, and an object can pass, the portal separating a first region containing the RFID system from a second region containing at least one of another transponder and another antenna.

3. The method as in claim 1, wherein each of the strips overlaps the adjacent strip by about fifty percent of the width of the adjacent strip.

4. The method as in claim 1, wherein the strips comprise a material that absorbs the radio signal.

5. The method as in claim 4, wherein the material comprises at least one of acrylonitrile butadiene styrene (ABS) plastic and ferrite powder.