US3833904A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Airborne switched array radar system
Assignee: Raytheon Co
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Filing: 1973-02-05
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Granted: 1974-09-03
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Expires: 1993-02-05
Abstract
Abstract An airborne radar system is disclosed utilizing multiple fixed antenna arrays mounted within the periphery of the aircraft to avoid aerodynamic modifications and optimumly placed to achieve 360* surveillance coverage. The arrays preferably include a fore mounted array, an aft mounted array, a port mounted array and a starboard mounted array for respectively firing beams in different azimuth sectors relative to the aircraft. Each array is comprised of dipole elements having phase shifters coupled thereto for steering a beam within the corresponding sector. The radar system may include both primary and secondary radar subsystems with the dipole elements of primary and secondary radar antennas being physically interleaved in the aforementioned antenna arrays. The primary radar antennas time share an exciter, transmitter, receiver and signal processor through switching devices. The secondary radar antennas (typically an IFF/SIF system) similarly time share transmitting and receiving equipment. Time allocation between antennas of each subsystem and between operational modes such as ''''search'''' or ''''track'''' is based on various factors such as mission objectives, current target characteristics and radar purpose. Time allocation is preferably determined by an ''''on line'''' stored program digital computer which generates a radar control command to define the parameters for each beam to be fired. Typically, the control command specifies (1) array (2) beam elevation (3) beam azimuth (4) total number of fill and data pulses (5) number of fill pulses (6) frequency and (7) pulse repetition rate or frequency. For each radar subsystem, this control command is interpreted by a radar control unit which responds by controlling various system elements including the exciter, transmitter, switches, phase shifters and duplexers to cause the defined beam to be fired. Each control command also preferably specifies parameters utilized to interpret the return beam including (8) ground doppler offset (9) threshold (10) range start time and (11) range end time. This latter information is employed by the radar control unit to enable primarily the receiver and signal processor to generate a beam return report which is then communicated by the radar control unit to the digital computer. The beam return report typically includes a header portion specifying the (1) clutter level and (2) jam level for each different frequency. The report also includes a subreport for each return beam which specifies (3) range (4) amplitude (5) doppler filter number and (6) ratio of signal to clutter plus noise. The digital computer then utilizes the beam return report to determine subsequent control commands.
Inventors
- 👤 R Gebhardt
- 👤 R Sidlo
- 👤 G Goldberg
- 👤 S Scheidler
- 👤 D King
- 👤 D Parke
- 👤 W Priester
- 👤 D Muchlinski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:03
CPC Classifications
H; H01; H01Q; H01Q1/00; H01Q1/27; H01Q1/28; G; G01; G01S; G01S13/00; G01S13/02; G01S13/06; G01S13/08; G01S13/10; G01S13/106; G01S13/12; G01S13/50; G01S13/52; G01S13/522; G01S13/524; G01S13/526; G01S13/528; G01S13/66; G01S13/70; G01S13/87; G01S13/872; H01Q25/00
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
287 words
An airborne radar system capable of exhibiting surveillance coverage throughout substantially 360* azimuth volume, said system comprising: an aircraft having a skin defining the periphery of said aircraft; first and second side antenna structures and fore and aft antenna structures each comprising an array of radiators oriented to define a substantially planar radiating face, said planar faces being substantially rectangular; means mounting each of said antenna structures on said aircraft and within the periphery thereof with said planar faces oriented toward different sectors of said 360* volume, said first and second side structures mounted with their planar faces oriented in opposite directions and fore and aft structures also mounted with their planar faces oriented in opposite directions and substantially perpendicular to said side structure planar faces, said aircraft including a fuselage and wings and said fore and aft antenna structures are respectively mounted at forward And aft positions in said fuselage with the planar faces thereof oriented substantially orthogonal to a longitudinal axis of said fuselage; said side structures are mounted in a forwardly tilted position to compensate for the pitch angle of the aircraft during flight; transmitter means for supplying signal energy to said antenna structures; receiver means for accepting signal energy from said antenna structures; switching means connected to said plurality of antenna structures for selectively coupling any one thereof to either said transmitter means or said receiver means; and digital logic means connected to said receiver means and responsive to signal energy received therefrom for controlling said switching means to connect said transmitter means to any one of said antenna structures and for controlling said transmitter means to produce bursts of signal energy of frequency and at intervals defined by said digital logic means.
Claim 2
Dependent Claim
287 words
An airborne radar system capable of exhibiting surveillance coverage throughout substantially 360* azimuth volume, said system comprising: an aircraft having a skin defining the periphery of said aircraft; first and second side antenna structures and fore and aft antenna structures each comprising an array of radiators oriented to define a substantially planar radiating face, said planar faces being substantially rectangular; means mounting each of said antenna structures on said aircraft and within the periphery thereof with said planar faces oriented toward different sectors of said 360* volume, said first and second side structures mounted with their planar faces oriented in opposite directions and fore and aft structures also mounted with their planar faces oriented in opposite directions and substantially perpendicular to said side structure planar faces, said aircraft including a fuselage and wings and said fore and aft antenna structures are respectively mounted at forward And aft positions in said fuselage with the planar faces thereof oriented substantially orthogonal to a longitudinal axis of said fuselage; said side structures are mounted in a forwardly tilted position to compensate for the pitch angle of the aircraft during flight; transmitter means for supplying signal energy to said antenna structures; receiver means for accepting signal energy from said antenna structures; switching means connected to said plurality of antenna structures for selectively coupling any one thereof to either said transmitter means or said receiver means; and digital logic means connected to said receiver means and responsive to signal energy received therefrom for controlling said switching means to connect said transmitter means to any one of said antenna structures and for controlling said transmitter means to produce bursts of signal energy of frequency and at intervals defined by said digital logic means.
Claim 3
Dependent Claim
52 words
The system of claim 1 wherein said digital logic means includes a stored program digital computer and a radar control unit and including means for coupling digital radar control commands from said computer to said radar control unit and digital beam return reports from said radar control unit to said digital computer.
Claim 4
Dependent Claim
148 words
The system of claim 2 wherein said radar control command includes information fields respectively identifying the characteristics of a radar beam to be fired including (1) frequency (2) number of pulses (3) pulse repetition rate and (4) azimuth angle; and wherein said transmitter means includes means responsive to said (1) frequency, (2) number of pulses and (3) pulse repetition rate information fields for producing a signal having the identified characteristics; and wherein said antenna structures each include a controllable phase shift means for steering a beam fired therefrom at a defined angle; and means responsive to said azimuth angle information field for controlling said switching means to apply said signal produced by said transmitter means to the antenna structure identified thereby and to control the phase shift means of the selected antenna structure to steer a beam therefrom at an angle defined by said azimuth angle information field.
Claim 5
Dependent Claim
37 words
The system of claim 3 wherein said receiver means further includes signal processor means including an ''''in-phase'''' and a ''''quadrature'''' signal path, each of said signal paths including means for converting analog signal energy to digital form.
Claim 6
Dependent Claim
52 words
The system of claim 4 wherein each of said signal paths further includes double MTI canceller means for producing a digital signal D representing the arithmetic operation: (An - Bn) - (Bn - Cn) where A, B, and C represent digitally expressed measures of signal energy accepted at points spaced in time.
Claim 7
Dependent Claim
89 words
The system of claim 5 including coherent integrator means comprised of a plurality (L) of digital filters each exhibiting a bandwidth PRF/L where PRF represents said pulse repetition rate; means applying said ''''in-phase'''' and ''''quadrature'''' signals D to each of said digital filters; means associated with each of said digital filters for producing an integrated output signal accumulated throughout a group of successive pulse repetition intervals; and noncoherent integrator means for summing each of said integrated output signals over a plurality of said groups of successive pulse repetition intervals.
Claim 8
Dependent Claim
68 words
The system of claim 3 wherein said receiver means includes sensing means passively sampling the signal level with respect to each of a plurality of frequencies; and wherein said radar control unit includes means for producing said beam return report and responsive to said sensing means for providing information fields in said beam return report indicating the signal level with respect to each of said plurality of frequeNcies.
Claim 9
Dependent Claim
54 words
The system of claim 2 wherein said radar control command includes information fields identifying the characteristics of a radar beam to be fired; and wherein said radar control unit includes means for controlling said switching means and said transmitter means to fire a beam from one of said array structures having said identified characteristics.
Claim 10
Dependent Claim
80 words
The system of claim 8 wherein said radar control command information fields respectively identify the characteristics of a radar beam to be fired including (1) frequency (2) number of pulses (3) pulse repetition rate and (4) azimuth angle; and wherein said radar control unit includes synchronizer means responsive to said radar control command for applying timing signals to said transmitter means to produce signal energy having the number of pulses and pulse repetition rate identified by said radar control command.
Claim 11
Dependent Claim
102 words
The system of claim 9 wherein said radar control unit further includes phase computer means responsive to said azimuth angle information field for developing a signal phi AZ where: phi AZ 2 pi (dF/c) sin theta and where F equals frequency, d represents the spacing between antenna structure radiators, C equals the propogation velocity of electromagnetic energy and theta equals the azimuth angle from antenna broadside; controllable phase shift means connected between said transmitter means and said antenna structure radiators for steering a beam therefrom at a defined angle; and means applying the said signal phi AZ to said phase shift means.
Claim 12
Dependent Claim
240 words
An airborne radar system capable of exhibiting surveillance coverage throughout substantially 360* azimuth volume, said system comprising: an aircraft having a skin defining the periphery of said aircraft; first and second side antenna structures and fore and aft antenna structures each comprising an array of radiators oriented to define a substantially planar radiating face; means mounting each of said antenna structures on said aircraft and within the periphery thereof with said planar faces oriented toward different sectors of said 360* volume, said first and second side structures mounted with their planar faces oriented in opposite directions and fore and aft structures also mounted with their planar faces oriented in opposite directions and substantially perpendicular to said side structure planar faces; transmitter means for supplying signal energy to said antenna structures; receiver means for accepting signal energy from said antenna structures and including signal processor means having analog to digital converter means for converting said accepted signal energy to digital form; switching means connected to said plurality of antenna structures for selectively coupling any one thereof to either said transmitter means or said receiver means; and digital logic means connected to said receiver means and responsive to signal energy received therefrom for controlling said switching means to connect said transmitter means to any one of said antenna structures and for controlling said transmitter means to produce bursts of signal energy of frequency and at intervals defined by said digital logic means.
Claim 13
Dependent Claim
240 words
An airborne radar system capable of exhibiting surveillance coverage throughout substantially 360* azimuth volume, said system comprising: an aircraft having a skin defining the periphery of said aircraft; first and second side antenna structures and fore and aft antenna structures each comprising an array of radiators oriented to define a substantially planar radiating face; means mounting each of said antenna structures on said aircraft and within the periphery thereof with said planar faces oriented toward different sectors of said 360* volume, said first and second side structures mounted with their planar faces oriented in opposite directions and fore and aft structures also mounted with their planar faces oriented in opposite directions and substantially perpendicular to said side structure planar faces; transmitter means for supplying signal energy to said antenna structures; receiver means for accepting signal energy from said antenna structures and including signal processor means having analog to digital converter means for converting said accepted signal energy to digital form; switching means connected to said plurality of antenna structures for selectively coupling any one thereof to either said transmitter means or said receiver means; and digital logic means connected to said receiver means and responsive to signal energy received therefrom for controlling said switching means to connect said transmitter means to any one of said antenna structures and for controlling said transmitter means to produce bursts of signal energy of frequency and at intervals defined by said digital logic means.
Claim 14
Dependent Claim
49 words
The system of claim 11 wherein said signal processor means includes double MTI canceller means for producing a digital signal D representing the arithmetic operation: (An - Bn) -(Bn - Cn) where A, B, and C represent digitally expressed measures of signal energy accepted at points spaced in time.
Claim 15
Dependent Claim
222 words
An airborne radar system capable of exhibiting surveillance coverage throughout substantially 360* azimuth volume, said system comprising: an aircraft having a skin defining the periphery of said aircraft; a plurality of antenna structures each comprising an array of radiators oriented to define a substantially planar radiating face; each of said array structures including a second array of radiators physically interleaved with said first named array of radiators; means mounting each of said antenna structures on said aircraft and within the periphery thereof with said planar faces oriented toward different sectors of said 360* volume; first transmitter means for supplying signal energy to said antenna structures; second transmitter means for supplying signal energy to said second array of radiators; first receiver means for accepting signal energy from said antenna structures; second receiver means for accepting signal energy from said second array of radiators; switching means connected to said plurality of antenna structures for selectively coupling any one thereof to either said transmitter means or said receiver means; and digital logic means connected to said receiver means and responsive to signal energy received therefrom for controlling said switching means to connect said transmitter means to any one of said antenna structures and for controlling said transmitter means to produce bursts of signal energy of frequency and at intervals defined by said digital logic means.
Claim 16
Dependent Claim
222 words
An airborne radar system capable of exhibiting surveillance coverage throughout substantially 360* azimuth volume, said system comprising: an aircraft having a skin defining the periphery of said aircraft; a plurality of antenna structures each comprising an array of radiators oriented to define a substantially planar radiating face; each of said array structures including a second array of radiators physically interleaved with said first named array of radiators; means mounting each of said antenna structures on said aircraft and within the periphery thereof with said planar faces oriented toward different sectors of said 360* volume; first transmitter means for supplying signal energy to said antenna structures; second transmitter means for supplying signal energy to said second array of radiators; first receiver means for accepting signal energy from said antenna structures; second receiver means for accepting signal energy from said second array of radiators; switching means connected to said plurality of antenna structures for selectively coupling any one thereof to either said transmitter means or said receiver means; and digital logic means connected to said receiver means and responsive to signal energy received therefrom for controlling said switching means to connect said transmitter means to any one of said antenna structures and for controlling said transmitter means to produce bursts of signal energy of frequency and at intervals defined by said digital logic means.
Claim 17
Dependent Claim
23 words
The system of claim 13 wherein said first and second arrays of radiators are respectively comprised of horizontally and vertically polarized dipole elements.
Claim 18
Dependent Claim
259 words
An airborne radar system capable of exhibiting surveillance coverage throughout a substantially 360* azimuth volume, said system comprising: an aircraft; a plurality of antenna structures each comprising an array of radiators oriented to define a substantially planar radiating face and including a controllable phase shift means for steering a beam fired therefrom at a defined angle; means mounting each of said antenna structures in said aircraft with the planar faces thereof respectively oriented toward different sectors of said 360* volume; transmitter means for selectively supplying signal energy in accordance with either a search beam mode format or a track beam mode format; receiver means for accepting signal energy from said antenna structures; switching means connected to said plurality of antenna structures for selectively coupling any one thereof to either said transmitter means or said receiver means; digital logic means responsive to signal energy received from said receiver means for producing digital signals constituting radar control command and including information fields respectively identifying the characteristics of a radar beam to be fired including (1) azimuth sector and beam angle and (2) beam mode; and means responsive to said radar control command for controlling said transmitter means to produce bursts of signal energy in accordance with the beam mode identified, for controlling said switching means to apply said signal energy produced by said transmitter means to the antenna structure corresponding to the identified azimuth sector, and for controlling the phase shift means of the identified antenna structure to steer a beam therefrom at an angle corresponding to said identified beam angle.
Claim 19
Dependent Claim
259 words
An airborne radar system capable of exhibiting surveillance coverage throughout a substantially 360* azimuth volume, said system comprising: an aircraft; a plurality of antenna structures each comprising an array of radiators oriented to define a substantially planar radiating face and including a controllable phase shift means for steering a beam fired therefrom at a defined angle; means mounting each of said antenna structures in said aircraft with the planar faces thereof respectively oriented toward different sectors of said 360* volume; transmitter means for selectively supplying signal energy in accordance with either a search beam mode format or a track beam mode format; receiver means for accepting signal energy from said antenna structures; switching means connected to said plurality of antenna structures for selectively coupling any one thereof to either said transmitter means or said receiver means; digital logic means responsive to signal energy received from said receiver means for producing digital signals constituting radar control command and including information fields respectively identifying the characteristics of a radar beam to be fired including (1) azimuth sector and beam angle and (2) beam mode; and means responsive to said radar control command for controlling said transmitter means to produce bursts of signal energy in accordance with the beam mode identified, for controlling said switching means to apply said signal energy produced by said transmitter means to the antenna structure corresponding to the identified azimuth sector, and for controlling the phase shift means of the identified antenna structure to steer a beam therefrom at an angle corresponding to said identified beam angle.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |