Patent US3680100A successfully refreshed from Google Patents.
US3680100A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Randomly phase coded antenna technique for search radar
Assignee: United States Department of the Navy
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Filing: 1970-12-15
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Granted: 1972-07-25
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Expires: 1990-12-15
Abstract
Abstract A search radar having an array antenna wherein the individual antenna array elements are energized by random phases having a beam forming matrix to sense direction dependent phase codes in the antenna far field, which phase codes are in turn used in correlation processing in the radar receiver for the purpose of obtaining angular resolution and radar sensitivity.
Inventors
- 👤 Hermann H Woerrlein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:38
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/06; G01S13/42; H; H01; H01Q; H01Q3/00; H01Q3/26; H01Q3/2605; H01Q3/30; H01Q3/34; H01Q3/40; G01S13/08; G01S13/10; G01S13/106; G01S2013/0236; G01S2013/0281
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
172 words
A method of detecting a target by radar, comprising the steps of: energizing a plurality of antenna elements so that each element radiates energy at substantially the same frequency as the other of said plurality of elements but at a phase which is controlled by a random or pseudo random process, said plurality of antenna elements thereby producing a total far field radiation pattern which is randomly changing, in time and in space, and which is substantially free of predominate lobes; synthesizing a multiplicity of signals which are representative of the directionally phase coded complex far field radiated by said plurality of antenna elements; receiving energy reflected by one or more targets in said far field radiated pattern and resolving the return from said targets at certain angles from all other returns by correlation processing, namely by correlating the received signals with the multiplicity of synthesized signals whereby a successful correlation of reflected signals with synthesized signals is indicative of the presence and direction of said targets in said far field pattern.
Claim 2
Independent Claim
172 words
A method of detecting a target by radar, comprising the steps of: energizing a plurality of antenna elements so that each element radiates energy at substantially the same frequency as the other of said plurality of elements but at a phase which is controlled by a random or pseudo random process, said plurality of antenna elements thereby producing a total far field radiation pattern which is randomly changing, in time and in space, and which is substantially free of predominate lobes; synthesizing a multiplicity of signals which are representative of the directionally phase coded complex far field radiated by said plurality of antenna elements; receiving energy reflected by one or more targets in said far field radiated pattern and resolving the return from said targets at certain angles from all other returns by correlation processing, namely by correlating the received signals with the multiplicity of synthesized signals whereby a successful correlation of reflected signals with synthesized signals is indicative of the presence and direction of said targets in said far field pattern.
Claim 3
Dependent Claim
142 words
A ''''silent'''' radar systEm comprising: antenna means for radiating energy to form a far field pattern that is directionally phase coded and randomly changing, in time and in space, and which is substantially free of predominate lobes; beam forming matrix means connected to said antenna means and having a plurality of outputs and functioning to produce signals at said plurality of outputs which are alternately representative of said radiated complex far field, the signals of individual outputs of said plurality of outputs being related to different directions from said antenna means and range resolution and correlation processing means connected to each of said plurality of outputs and functioning to provide a signal informative of the presence, range, and angular coordinates of a target when correlation occurs between the signals representative of the radiated far field pattern and of the received radar signal.
Claim 4
Dependent Claim
142 words
A ''''silent'''' radar systEm comprising: antenna means for radiating energy to form a far field pattern that is directionally phase coded and randomly changing, in time and in space, and which is substantially free of predominate lobes; beam forming matrix means connected to said antenna means and having a plurality of outputs and functioning to produce signals at said plurality of outputs which are alternately representative of said radiated complex far field, the signals of individual outputs of said plurality of outputs being related to different directions from said antenna means and range resolution and correlation processing means connected to each of said plurality of outputs and functioning to provide a signal informative of the presence, range, and angular coordinates of a target when correlation occurs between the signals representative of the radiated far field pattern and of the received radar signal.
Claim 5
Dependent Claim
48 words
The ''''silent'''' radar of claim 2 wherein said radiated energy is varied in pulse repetition frequency and also because said far field pattern is substantially free of predominate lobes, the personnel on said targets are more likely to regard said ''''silent'''' radar surveillance as being noise or jamming.
Claim 6
Dependent Claim
87 words
The ''''silent'''' radar of claim 2 wherein said range resolution and correlation processing means includes a switching means, a storage device having a multiplicity of output taps and a multiplicity of correlation mixers connected to said multiplicity of output taps, said switching means being controlled to connect each of said plurality of outputs to said storage device when said antenna means is radiating energy and to connect each of said plurality of outputs to said multiplicity of correlation mixers when said antenna means is not radiating energy.
Claim 7
Dependent Claim
33 words
The ''''silent'''' radar of claim 4 wherein said antenna means includes a plurality of array antenna elements, each element of which is connected through a transmit-receive (TR) means to a source of energy.
Claim 8
Dependent Claim
66 words
The ''''silent'''' radar of claim 5 wherein said TR means has an output which is connected to said beam forming matrix means and functions to connect said antenna elements to said beam forming matrix when said antenna is not radiating energy and to pass to said beam forming matrix a small portion of the energy passing through said TR means when said antenna is radiating energy.
Claim 9
Dependent Claim
45 words
The ''''silent'''' radar of claim 6 which further includes signal processing means which are connected to the outputs of said multiplicity of correlation mixers and functions to improve the signal-to-noise ratio of said signal informative of the presence, range, and angular coordinates of a target.
Claim 10
Dependent Claim
20 words
The ''''silent'''' radar of claim 7 which further includes a display and record section connected to said signal processing means.
Claim 11
Dependent Claim
18 words
The ''''silent'''' radar of claim 8 wherein said beam forming matrix means includes a Butler beam forming matrix.
Claim 12
Dependent Claim
102 words
A ''''silent'''' radar system comprising: antenna means for radiating energy to form a far field pattern that is directionally phase coded and randomly changing, in time and in space, and which is substantially free of predominate lobes; beam forming matrix means connected to said antenna means and functioning to sense the directionally phased coding of said far field pattern; range resolution and correlation processing means connected to said beam forming matrix means and functioning to provide range resolution by sensing the time when correlation occurs, and to provide angular resolution due to the multiplicity of correlation processing channels implemented for different directions.
Claim 13
Dependent Claim
102 words
A ''''silent'''' radar system comprising: antenna means for radiating energy to form a far field pattern that is directionally phase coded and randomly changing, in time and in space, and which is substantially free of predominate lobes; beam forming matrix means connected to said antenna means and functioning to sense the directionally phased coding of said far field pattern; range resolution and correlation processing means connected to said beam forming matrix means and functioning to provide range resolution by sensing the time when correlation occurs, and to provide angular resolution due to the multiplicity of correlation processing channels implemented for different directions.
Claim 14
Dependent Claim
36 words
The ''''silent'''' radar of claim 10 and further including a display section means connected to said range resolution and correlation processing means and functioning to present a display representative of said provided directional and range resolutions.
References Cited (Backward Citations)
US3546700A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |