REMOTELY POWERED TRANSPONDER HAVING A DIPOLE ANTENNA ARRAY

• US 3,852,755 A
• Filed: 02/12/1973
• Issued: 12/03/1974
• Est. Priority Date: 07/22/1971
• Status: Expired due to Term

• Current Assignee: John C. Murray, Nathan Freedman, Works George A
• Original Assignee: John C. Murray, Nathan Freedman, Works George A
• Inventors: Works, George A., Murray, John C., Freedman, Nathan
• Primary Examiner(s): Lieberman, Eli
• Application Number:
  US05/331,920
• Time in Patent Office: 659 Days
• Field of Search: 343/6.5SS,6.8,701,703,815,846
• US Class Current: 343/701
• CPC Class Codes: B07C 3/12 using electric or electronic detecting means B07C3/14 takes precedence
• CPC Class Codes: B61L 25/045 using reradiating tags
• CPC Class Codes: B65G 47/49 without bodily contact between article or load carrier and automatic control device , e.g. the destination marks being electrically or electronically detected
• CPC Class Codes: G01S 13/758 using a signal generator powered by the interrogation signal
• 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: H01Q 3/46 Active lenses or reflecting arrays

Abstract

A transponder having a novel circuit for the extraction of power from an incident interrogating beam of electromagnetic energy, the extracted power being utilized to operate a digital coding circuit. The transponder further comprises an oscillator circuit for developing a train of pulses of electromagnetic energy with successive pulses occurring in a coded format in accordance with a digital code imparted by the digital coding circuit. The transponder is of sufficiently small size to be affixed in the form of a tag to automobiles, personnel, containers and other objects to be identified. An interrogation system for utilizing the electronic tag is also disclosed.

Claims

1. In combination:

a reflector;

an array of radiating elements each of which comprises a dipole type structure positioned in front of and spaced apart from said reflector;

a plurality of serially connected diodes, each of said diodes being couple to respective ones of said radiating elements at the midpoints thereof;

means interposed between said array and said reflector for positioning said radiating elements a uniform distance in front of said reflector Such that an electric field provided by the radiating elements of said array in response to radiation incident upon said array and said reflector induces a voltage across said diodes.

2. The combination according to claim 1 wherein said positioning means includes means for insulating said array of radiating elements from said reflector, said combination further comprising conductor means connecting with said diodes for extracting power therefrom, said conducting means extending through said insulating means towards said reflector.

3. In combination:

a reflector;

an array of radiating elements spaced apart from said reflector;

insulating means interposed between said array and said reflector;

diode means coupled to respective ones of said radiating elements such that an electric field provided by a radiating element of said array in response to radiation incident upon said aray induces a voltage across said diode means;

first conductor means connecting with said diode means for extracting power therefrom, said conducting means extending through said insulating means towards said reflector; and

second conductor means interconnecting one of said first conductor means with a second of said first conductor means, said second conductor means being spaced from said reflector to provide capacitance between said second conductor means and said reflector, said capacitance cooperating with inductance of said first conductor means to serve as a filter for extracting a direct component of said power and impeding alternating components of said power.

4. A system for extracting energy from radiation incident thereupon, said system comprising:

a reflector of said radiation;

an array of radiating elements each of which comprises a dipole type structure, said radiating elements being spaced apart from said reflector and positioned relative to said reflector for intercepting rays of said radiant energy reflected from said reflector towards said radiating elements;

a plurality of serially connected diodes, each of said diodes being coupled to respective ones of said radiating elements at the midpoints thereof; and

means coupled to said radiating elements for conducting rectified current of said incident radiation away from said radiating elements.

5. A system according to claim 4 wherein said conducting means is spaced apart from said reflector to provide a filtering of said rectified current.

6. A system according to claim 4 wherein said conducting means is structured to provide for inductance for said rectified current, and said conducting means is spaced apart and insulated from said reflector to provide capacitance for said rectified current, said inductance and said capacitance having preselected magnitudes for filtering said rectified current.

7. A system according to claim 6 wherein said array of radiating elements comprises spiral-shaped elements.