System for detecting and measuring parameters of passive transponders

• US 8,072,310 B1
• Filed: 06/02/2008
• Issued: 12/06/2011
• Est. Priority Date: 06/05/2007
• Status: Expired due to Fees

• Current Assignee: Pulsed Indigo Development LLC
• Original Assignee: Pulsed Indigo Inc.
• Inventors: Everhart, Howard Richard
• Primary Examiner(s): Wu, Daniel
• Assistant Examiner(s): OTT, FREDERICK R
• Application Number:
  US12/156,535
• Time in Patent Office: 1,282 Days
• Field of Search: 340/10.1, 340/572.1, 340/572.4, 340/572.5, 340/572.7, 340/572.8, 600/325, 600/327, 600/422, 600/423
• US Class Current: 340/10.1
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/45 Transponders
• CPC Class Codes: H04B 5/73 for taking measurements, e.g. using sensing coils

Abstract

A detection and paramedic measuring system using a transponder composed of passive components and pulse inductive interrogation is disclosed. A methodology based on measuring the quality factor of the transponder is employed to detect a specific species of transponder or measure a parameter that alters the transponders quality factor.

Claims

1. A wireless passive transponder system, comprising:

an inductively activated passive transponder which has a known resonate center frequency and bandwidth;

an inductive pulse generator which excites said transponder using a single magnetic pulse thereby causing said transponder to oscillate at said resonate center frequency;

a receiver which includes an amplitude modulation detector which extracts a demodulated signal of said oscillation of said transponder;

a measuring circuit which converts a decay rate of said demodulated signal to said transponder'"'"'s bandwidth;

a computational unit which replaces or augments said measuring circuit;

said computational unit controls a sequencing of pulses from said inductive pulse generator to form a collection of said receiver'"'"'s output data to form an interrogation cycle;

said computational unit averages or processes multiple said interrogation cycles to reduce noise to improve measurement accuracy of said transducer bandwidth, and

said computational unit uses multiple randomly varying times between said interrogation cycles thereby reducing interference from background signals to improve measurement accuracy of said transducer bandwidth.

2. The system according to claim 1, wherein said transponder comprises an inductor and capacitor in parallel resonance shunted by a parametric sensitive resistance such that said transponder'"'"'s bandwidth is varied there by forming a parametric measuring transponder.

3. The system according to claim 1, wherein said transponder is comprised of a mechanical resonator activated with a magnetic transducer.

4. The system according to claim 1 that further includes a loop antenna which is an integral part of said inductive pulse generator and alternately said loop antenna being shared with said receiver.

5. The system according to claim 1 wherein said computational unit functions as said amplitude modulation detector.

6. The system according to claim 1 wherein said computational unit has a storage interface with prerecorded characteristics of said transponder, thereby allowing said computational unit to convert said transducer bandwidth to a parameter value for storage and/or display.

7. A wireless parametric measuring system comprising:

an electromagnetic passive resonate transponder with an incorporated element that alters said transponder'"'"'s resonate bandwidth or quality factor based on a parameter being measured;

an inductive pulse generator and antenna that excites said transponder causing said transponder to ring at a resonate frequency;

a receiver and an antenna that detects said ringing of said transponder and measures a decay rate to determine a resonate bandwidth;

wherein said excitation and said receive antennas are combined into a single element;

wherein said center frequency and bandwidth of said transponder is fixed and said system is used to detect the presence of said transponder in a detection field where multiple transponders may be present;

wherein each transponder from said multiple transponders has a different center frequency;

a computational or display element that provides access to said resonate bandwidth to provide parametric data regarding said electromagnetic passive resonate transponder(s), and

said computational element averages or processes multiple interrogation cycles to reduce noise to improve measurement accuracy of said transducer bandwidth.

8. The wireless parametric measuring system according to claim 7 wherein said transponder is composed of an inductor and a capacitor in parallel resonance shunted by a parametric sensitive resistance.

9. The wireless parametric measuring system according to claim 7 wherein said computational unit is supplied with predefined known characteristics of transponder that allow said computational unit to convert said detected bandwidth to said measured parameter to matching predefined known characteristics.

10. The wireless parametric measuring system according to claim 7 wherein said parametric data is stored in either raw or converted format in said computational element for later playback.

11. The wireless parametric measuring system according to claim 7 wherein said resonate bandwidth has a center frequency for each transponder.

12. The wireless parametric measuring system according to claim 7 wherein said incorporated element is a parametric resistive sensitive element.