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US5047776A Expired / Lapsed US ⏱️ 0.0 years remaining

Multibeam optical and electromagnetic hemispherical/spherical sensor

Assignee: Raytheon Co
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Filing: 1990-06-27
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Granted: 1991-09-10
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Expires: 2010-06-27
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Abstract

Abstract An optical spherical Luneburg lens is described which is also useful for millimeter wave and microwave operation, which can provide a multitude of simultaneously acting receiving beams over a hemispherical or spherical field of view. When used in conjunction with surface mounted optical/radio frequency pickup elements, the lens can be employed in a passive target detection system of unique field of coverage and sensitivity. The lens comprises a center sphere of refractive index of approximately √2, around which are arranged in concentric shells of aerogel material. The aerogel material of the respective shells is fabricated to obtain a particular index of refraction approximately equal to (2-(r/r 0 ) 2 ) 1/2 , where r is the radius of the shell and r 0 is the radius of the lens assembly. The lens can be employed in a system providing dual mode simultaneous optical and radio frequency operation with a single aperture. Its multibeam simultaneous detection capability can provide an input to advanced digital signal processors to perform automatic image and pattern recognition for commercial and military sensor systems. It may also be used as an active sensor using optical or radio frequency energy.

Inventors

  • 👤 Howard Baller

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 21:22
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/10; H; H01; H01Q; H01Q15/00; H01Q15/02; H01Q15/08; G01; G01S; G01S3/00; G01S3/02; G01S3/04; G01S3/043; G01S3/78; G01S3/782; G01S3/783; G01S3/784

Claims Analysis

Total Claims: 33
Claim 1
Independent Claim 127 words
A lens comprising a plurality of concentric dielectric shells of aerogel material, arranged around a center sphere of material characterized by a refractive index of approximately √2, and wherein said lens has an outer radium r o , and the radius of each shell is characterized by a typical radium value r, the respective refractive index value of each shell being an approximation to the formula (2-(r/r o ) 2 ) 1/2 , said lens characterized in that planar electromagnetic wave fronts incident on said lens from a distant source are imaged at a focus point on the lens surface at the end of the diameter of the lens in the direction of the incoming wave front and that the lens provides electro-optical and radio frequency operation.
Claim 2
Dependent Claim 127 words
A lens comprising a plurality of concentric dielectric shells of aerogel material, arranged around a center sphere of material characterized by a refractive index of approximately √2, and wherein said lens has an outer radium r o , and the radius of each shell is characterized by a typical radium value r, the respective refractive index value of each shell being an approximation to the formula (2-(r/r o ) 2 ) 1/2 , said lens characterized in that planar electromagnetic wave fronts incident on said lens from a distant source are imaged at a focus point on the lens surface at the end of the diameter of the lens in the direction of the incoming wave front and that the lens provides electro-optical and radio frequency operation.
Claim 3
Dependent Claim 30 words
The lens of claim 1 comprising a plurality of optical sensor elements, each responsive to the light energy imaged at a particular point on the external surface of said lens.
Claim 4
Dependent Claim 27 words
The lens of claim 2 wherein said optical sensor elements comprise semiconductor detector elements bonded to the external surface of said lens at said particular focus points.
Claim 5
Dependent Claim 33 words
The lens of claim 2 wherein said optical sensor elements comprise optical fibers arranged for conducting the light imaged at said focus points to optically sensitive detector elements, one for each focus point.
Claim 6
Dependent Claim 36 words
The lens of claim 4 wherein said optically sensitive detector elements comprise a monolithic array of semiconductor detectors fabricated on a common substrate remotely located from the spherical surface, with signals transmitted thereto by optical fibers.
Claim 7
Dependent Claim 36 words
The lens of claim 1 further comprising a plurality of millimeter wave or microwave sensor elements responsive to the millimeter wave or microwave energy imaged at said focus points on the exterior surface of said lens.
Claim 8
Dependent Claim 18 words
The lens of claim 6 wherein said sensor elements comprise a detector diode and a microwave metal horn.
Claim 9
Dependent Claim 14 words
The lens of claim 1 wherein said center sphere material is an aerogel material.
Claim 10
Dependent Claim 182 words
A sensor system comprising: a spherical lens comprising a plurality of concentric dielectric shells of aerogel material, arranged around a center sphere of material characterized by a refractive index of approximately √2, and wherein said lens has an outer surface radius of r o , and wherein each shell is characterized by a typical radius value r, the respective refractive index value of each shell being approximately equal to (2-(r/r o ) 2 ) 1/2 , said lens being characterized in that planar electromagnetic wave fronts incident on said lens from a distance source are imaged at a point on the lens surface at the end of the diameter of the lens in the direction of the incoming wave fronts and that the lens provides electro-optical and radio frequency operation; a plurality of sensor elements each responsive to the energy imaged at a desired focus point on the external surface of said lens and providing an electrical signal indicative of the beam energy imaged at the focal point; and signal processing means responsive to the sensor electrical signals for processing said signals.
Claim 11
Dependent Claim 182 words
A sensor system comprising: a spherical lens comprising a plurality of concentric dielectric shells of aerogel material, arranged around a center sphere of material characterized by a refractive index of approximately √2, and wherein said lens has an outer surface radius of r o , and wherein each shell is characterized by a typical radius value r, the respective refractive index value of each shell being approximately equal to (2-(r/r o ) 2 ) 1/2 , said lens being characterized in that planar electromagnetic wave fronts incident on said lens from a distance source are imaged at a point on the lens surface at the end of the diameter of the lens in the direction of the incoming wave fronts and that the lens provides electro-optical and radio frequency operation; a plurality of sensor elements each responsive to the energy imaged at a desired focus point on the external surface of said lens and providing an electrical signal indicative of the beam energy imaged at the focal point; and signal processing means responsive to the sensor electrical signals for processing said signals.
Claim 12
Dependent Claim 16 words
The sensor system of claim 9 wherein said sensor elements are responsive to optical light energy.
Claim 13
Dependent Claim 20 words
The sensor system of claim 9 wherein said sensor elements are responsive to millimeter wave signals incident on said lens.
Claim 14
Dependent Claim 19 words
The sensor system of claim 9 wherein said sensor elements are responsive to microwave signals incident on said lens.
Claim 15
Dependent Claim 35 words
The sensor system of claim 9 wherein said lens is characterized by a hemispherical field of view, the sensor elements being arranged to respond to beams incident on the lens over a hemispherical portion thereof.
Claim 16
Dependent Claim 36 words
The sensor system of claim 9 wherein said lens is characterized by a substantially spherical field of view, the sensor elements being arranged to beams incident on the lens over the spherical surface of said lens.
Claim 17
Dependent Claim 20 words
The sensor system of claim 9 wherein said processing means comprises means for processing simultaneously signals from said sensor elements.
Claim 18
Dependent Claim 82 words
The sensor system of claim 9 wherein said processing means comprises means for sampling the electrical signals generated by said sensor elements under control of pattern control signals to provide sampled sensor signals, means for generating said pattern control signals to control the sampling of said electrical signals to sample the respective beam outputs in a desired manner, means for digitizing the sampled sensor signals, and a digital computer responsive to said digitized signals to process the data received by said lens.
Claim 19
Dependent Claim 18 words
The sensor system of claim 9 wherein said center sphere material of said lens is an aerogel material.
Claim 20
Dependent Claim 69 words
The sensor system of claim 9 wherein said signal processing means comprises: means for sampling the electrical signals from one or more selected ones of said sensor elements in response to sample control signals to sample the responses from one or more selected beams focused at particular selected directions; means for converting the sampled signals to digital signal samples; and a digital computer for processing the digital signal samples.
Claim 21
Dependent Claim 30 words
The sensor system of claim 9 wherein said signal processing means further comprises a pattern scanner for generating said sample control signals to achieve one or more particular scan patterns.
Claim 22
Dependent Claim 228 words
A radar system comprising: a spherical lens comprising a plurality of concentric dielectric shells of aerogel material, arranged around a center sphere of material characterized by a refractive index approximately √2 and wherein said lens has an outer radius of r o , and wherein the radius of each shell is characterized by a typical radius value r, the respective refractive index value of each shell being approximately equal to (2-(r/r o ) 2 ) 1/2 , said lens characterized in that planar electromagnetic wave fronts incident on said lens from a distant source are imaged at a focus point on the lens surface at the end of the diameter of the lens in the direction of the incoming wave fronts and that the lens provides electro-optical and radio frequency operation; a plurality of radio frequency energy transducers located at a plurality of focus points about at least a portion of the external surface of the lens, said energy transducers for converting radio frequency energy received at said focus points into electrical signals and vice versa; a transmitter coupled to said transducers for selectively exciting one or more of the transducers to produce one or more transmit beams, each corresponding to a particular transducer; and a receiver and signal processor coupled to said transducer to selectively receive return signals from one or more transducers and process said signals.
Claim 23
Dependent Claim 228 words
A radar system comprising: a spherical lens comprising a plurality of concentric dielectric shells of aerogel material, arranged around a center sphere of material characterized by a refractive index approximately √2 and wherein said lens has an outer radius of r o , and wherein the radius of each shell is characterized by a typical radius value r, the respective refractive index value of each shell being approximately equal to (2-(r/r o ) 2 ) 1/2 , said lens characterized in that planar electromagnetic wave fronts incident on said lens from a distant source are imaged at a focus point on the lens surface at the end of the diameter of the lens in the direction of the incoming wave fronts and that the lens provides electro-optical and radio frequency operation; a plurality of radio frequency energy transducers located at a plurality of focus points about at least a portion of the external surface of the lens, said energy transducers for converting radio frequency energy received at said focus points into electrical signals and vice versa; a transmitter coupled to said transducers for selectively exciting one or more of the transducers to produce one or more transmit beams, each corresponding to a particular transducer; and a receiver and signal processor coupled to said transducer to selectively receive return signals from one or more transducers and process said signals.
Claim 24
Dependent Claim 18 words
The radar system of claim 20 wherein said center sphere material of said lens is an aerogel material.
Claim 25
Dependent Claim 39 words
The radar system of claim 20 wherein said portion of the external lens surface about which the transducers are located extends over a hemisphere of said lens surface, wherein the system is characterized by a hemispherical field of view.
Claim 26
Dependent Claim 30 words
The radar system of claim 20 wherein said transducers are dispersed over the spherical surface of said lens, whereby said system is characterized by a substantially spherical field of view.
Claim 27
Dependent Claim 252 words
A sensor system comprising: a spherical lens comprising a plurality of concentric dielectric shells of aerogel material, arranged around a center sphere of material characterized by a refractive index approximately √2 and wherein said lens has an outer radius of r o , and wherein the radius of each shell is characterized by a typical radius value r, the respective refractive index value of each shell being approximately equal to (2-(r/r o ) 2 ) 1/2 , said lens characterized in that planar electromagnetic wave fronts incident on said lens from a distant source are imaged at a focus point on the lens surface at the end of the diameter of the lens in the direction of the incoming wave fronts; a plurality of optical sensors located at a plurality of sensor focus points about at least a portion of the external surface of the lens, said energy transducer for converting optical energy into electrical signals indicative of energy received at said focus points; a plurality of optical transducers for emitting light energy at particular transmit focus points dispersed among said sensor focus points for emitting optical light energy in response to electrical transducer signals; a transmitter comprising means for generating said electrical transducer signals for selectively exciting one or more of the transducers to produce one or more transmit beams, each corresponding to a particular transducer; and a receiver and signal processor coupled to said optical sensors to selectively receive signals from one or more sensor elements and process said signals.
Claim 28
Dependent Claim 252 words
A sensor system comprising: a spherical lens comprising a plurality of concentric dielectric shells of aerogel material, arranged around a center sphere of material characterized by a refractive index approximately √2 and wherein said lens has an outer radius of r o , and wherein the radius of each shell is characterized by a typical radius value r, the respective refractive index value of each shell being approximately equal to (2-(r/r o ) 2 ) 1/2 , said lens characterized in that planar electromagnetic wave fronts incident on said lens from a distant source are imaged at a focus point on the lens surface at the end of the diameter of the lens in the direction of the incoming wave fronts; a plurality of optical sensors located at a plurality of sensor focus points about at least a portion of the external surface of the lens, said energy transducer for converting optical energy into electrical signals indicative of energy received at said focus points; a plurality of optical transducers for emitting light energy at particular transmit focus points dispersed among said sensor focus points for emitting optical light energy in response to electrical transducer signals; a transmitter comprising means for generating said electrical transducer signals for selectively exciting one or more of the transducers to produce one or more transmit beams, each corresponding to a particular transducer; and a receiver and signal processor coupled to said optical sensors to selectively receive signals from one or more sensor elements and process said signals.
Claim 29
Dependent Claim 18 words
The sensor system of claim 24 wherein said center sphere material of said lens is an aerogel material.
Claim 30
Dependent Claim 41 words
The sensor system of claim 24 wherein said portion of the external lens surface about which the sensors and transducers are located extends over a hemisphere of said lens surface, wherein the system is characterized by a hemispherical view of view.
Claim 31
Dependent Claim 33 words
The sensor system of claim 24 wherein said optical sensors and optical transducers are dispersed about the spherical surface of said lens, whereby said system is characterized by a spherical field of view.
Claim 32
Dependent Claim 127 words
The sensor system of claim 24 further comprising a plurality of radio frequency energy transducers located at a plurality of radio frequency focus points disposed over at least a portion of the external surface of said lens, said energy transducers for converting radio frequency energy received at said radio frequency energy received at said radio frequency focus points into electrical signals and vice versa; a radio frequency transmitter coupled to said radio frequency transducers for selectively exciting one or more of said transducers to produce one or more transmit beams, each corresponding to a particular beam; and a radio frequency receiver and signal processor coupled to said radio frequency transducers to selectively receive radio frequency return signals from one or more said transducers and process said signals.
Claim 33
Dependent Claim 18 words
The system of claim 24 wherein said optical transducers each comprise a means for emitting laser light energy.

References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-09-09 1995-03-11 1995-09-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-09-09 1999-03-11 1999-09-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-09-09 2003-03-11 2003-09-10 $7700.00 Window Closed / Lapsed

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