SYSTEM FOR IDENTIFYING OBJECTS USING AN ENCODING ARRAY FOR EACH OBJECT

• US 3,691,557 A
• Filed: 09/22/1969
• Issued: 09/12/1972
• Est. Priority Date: 09/22/1969
• Status: Expired due to Term

• Current Assignee: Advanced Micro Devices, Inc.
• Original Assignee: 91711,, James Nickolas Constant, 1603 Danbury Dr.
• Inventors: James Nickolas Constant, 1603 Danbury Dr., 91711,
• Primary Examiner(s): Malcolm F. Hubler
• Application Number:
  US04/870,598
• Time in Patent Office: 1,086 Days
• Field of Search: 343/6.5SS,6.8,5CM,713,810,812
• US Class Current: 342/25.00F
• CPC Class Codes: G01S 13/751 wherein the responder or reflector radiates a coded signal
• CPC Class Codes: G01S 13/753 using frequency selective elements, e.g. resonator
• CPC Class Codes: G01S 13/90 using synthetic aperture techniques , e.g. synthetic aperture radar [SAR] techniques

Abstract

A system for identifying binary coded objects. A passive encoding array for an object and having dipoles at selected dipole locations in the array, and a synthetic aperture radar for scanning the arrays as the objects move relative to the radar. The radar output is a pulse train with pulses corresponding to dipoles of arrays illuminated by the radar.

Claims

1. In a system for identifying objects with a binary code, the combination of:

a plurality of passive encoding arrays with an array for each object, each of said arrays having a plurality of dipole locations with dipoles disposed at selected locations, with the presence and absence of dipoles at dipole locations comprising a binary code for the object; and

a coherent synthetic aperture radar including transmitter, receiver, local oscillator and data processor, said transmitter including an antenna for directing the transmitter output to a zone where an array moves relative to the radar, with the dipoles resonating when illuminated by the transmitter, said receiver including an antenna for receiving signals from resonating dipoles, with said oscillator providing a common reference frequency for said transmitter and receiver, and with said data processor having the receiver output as an input for providing a digital pulse train with a pulse for each dipole of an array illuminated by the transmitter.

2. A system as defined in claim 1 wherein said dipoles of an array are electrical conductors of uniform length and positioned in a dielectric.

3. A system as defined in claim 1 wherein the spacing of dipole locations of an array for a system operating at a particular wavelength and frequency is substantially equal to the antenna aperture along the path of relative motion of radar and array.

4. A system as defined in claim 1 wherein said dipoles are disposed substantially parallel to each other and are of a length substantially equal to one-half the wavelength of the operating frequency of the transmitter output.

5. A system as defined in claim 1 wherein the spacing of dipole locations is substantially a linear dependence of the antenna aperture along the path of relative motion of the radar and array and is substantially independent of wavelength and range.