US3835448A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multibeam steering system for a circular section acoustic transducer array
Assignee: Thales SA
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Filing: 1973-04-19
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Granted: 1974-09-10
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Expires: 1993-04-19
Abstract
Abstract A system for the accurate multibeam steering, prior to the beams forming by electronic means, of a circular-section acoustic transducer array. The electric signals derived from transducers aranged in columns are processed and multiplexed in time-division fashion using an electronic switch, then sampled at a variable frequency F1 before being applied to an interpolation filter whose output is resampled at a fixed frequency F2. The frequency F1 is made variable in dependance of a setpoint value; the interval between these two frequencies F1 and F2 producing an offset between the instants of sampling, and thus making it possible to modify to beam steering. The system is applicable to the multibeam steering and stabilisation in the azimuthal plane, of an acoustic transmit and/or receive transducer array.
Inventors
- 👤 J Bertheas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:40
CPC Classifications
H; H01; H01Q; H01Q3/00; H01Q3/24; H01Q3/242; G; G01; G01S; G01S3/00; G01S3/80; G01S3/802; G01S3/809; G01S7/00; G01S7/52; G01S7/52003; G10; G10K; G10K11/00; G10K11/18; G10K11/26; G10K11/34; G10K11/341; G10K11/346
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
314 words
A multibeam steering system for a circular section acoustic transducer array composed of eleCtro-acoustic transducers distributed at the periphery in N columns spaced from one another by half a wavelength of the mean operating frequency, which system, comprises: an input processor (2) for converting the N electrical signals (A1, --- AN) received from said transducers into signal complex components comprising two groups respectively of real parts X and imaginary parts Y, a master clock (9) for producing a timing pilot signal of a predetermined frequency Fo, an operation control unit (8) connected to said clock for producing control signals, on one hand, in a predetermined sequence of discrete signals (P1, --- PN), on the other hand one signal of variable frequency F1 depending on a set point value C, and another of fixed frequency F2 applied to signal transmission channels and further producing synchronising signals S applied to a beam-forming output processor (7), two parallel said signal transmission channels interconnecting said input processor outputs to said output processor inputs, each said channel comprising, in a series connection, a timedivision multiplex system (3) coupled by its inputs to receive respectively one of said complex part signals (X1, --- XN; Y1, --- YN) under control of a descrete signal determined by said set point value C in said control signals predetermined sequence (P1, --- PN), a first sampling circuit (4) actuated by said signal of variable frequency F1, a filter (5) for carrying out interpolation between successively applied signals, a second sampling circuit (6) actuated by said another signal of fixed frequency F2 having a value equal or higher than the product of the number N of said transducer columns by the frequency band B of the propagated acoustic signals, and said output processor (7) connected to the respective outputs of the second sampling circuits (6) and to said operation control unit (8) for beam forming.
Claim 2
Dependent Claim
314 words
A multibeam steering system for a circular section acoustic transducer array composed of eleCtro-acoustic transducers distributed at the periphery in N columns spaced from one another by half a wavelength of the mean operating frequency, which system, comprises: an input processor (2) for converting the N electrical signals (A1, --- AN) received from said transducers into signal complex components comprising two groups respectively of real parts X and imaginary parts Y, a master clock (9) for producing a timing pilot signal of a predetermined frequency Fo, an operation control unit (8) connected to said clock for producing control signals, on one hand, in a predetermined sequence of discrete signals (P1, --- PN), on the other hand one signal of variable frequency F1 depending on a set point value C, and another of fixed frequency F2 applied to signal transmission channels and further producing synchronising signals S applied to a beam-forming output processor (7), two parallel said signal transmission channels interconnecting said input processor outputs to said output processor inputs, each said channel comprising, in a series connection, a timedivision multiplex system (3) coupled by its inputs to receive respectively one of said complex part signals (X1, --- XN; Y1, --- YN) under control of a descrete signal determined by said set point value C in said control signals predetermined sequence (P1, --- PN), a first sampling circuit (4) actuated by said signal of variable frequency F1, a filter (5) for carrying out interpolation between successively applied signals, a second sampling circuit (6) actuated by said another signal of fixed frequency F2 having a value equal or higher than the product of the number N of said transducer columns by the frequency band B of the propagated acoustic signals, and said output processor (7) connected to the respective outputs of the second sampling circuits (6) and to said operation control unit (8) for beam forming.
Claim 3
Dependent Claim
68 words
A system as claimed in claim 1, wherein each input of the multiplex system (3) comprises a separate analogue gate, the said first (4) and said second (6) sampling circuits being . . . of sample and hold type, and said interpolation filter (5) being a low-pass filter suppressing the harmonics due to sampling and having a cut-off frequency of less than half the said fixed frequency F2.
Claim 4
Dependent Claim
187 words
A system as claimed in claim 1, wherein the operation control unit (8) comprises a digital counter (10) of m + p digits receiving said timing pilot signal of a predetermined frequency Fo equal to 2mF2, m and p being positive integers such that 2p represents said number N of columns of transducers and 2m p the number of discrete angular positions which a beam can take within the 360* sweep, the p digits of highest weight from said counter constituting said synchronising signals S, the m digits of lowest weight being applied to a first decoding circuit (11) producing said fixed frequency F2, the whole of the m + p digits constituting a binary number M2 being furthermore applied to an adder (12) also supplied from a coder (13) with the binary set point value C likewise coded in m + p digits and producing a binary number M1 equal to M2+C, which is applied to a second decoding circuit (14) generating said variable frequency F1 and said discrete signals (P1 . . . PN) the latter actuating the input gates to said multiplex systems (3).
Claim 5
Dependent Claim
119 words
A system as claimed in claim 3, in which said operation control unit provides azimuthal stabilisation, wherein the circuits producing the discrete control signals applied to said multiplex systems (3) and the variable frequency signal F1, comprise, connected in series after said digital counter (10), an intermediate decoder (15) which, every time the counter passes a selected value, applies a signal transferring the set point values contained in said coder (13) to a so-called ''''relative'''' counter (16) made up of synchronisable trigger stages which receive said set point values at their respective preset inputs, and which receive said timing pilot signal Fo, at its counting input the output signals from the counter being applied to said second decoder (14).
Claim 6
Dependent Claim
88 words
A system as claimed in claim 4, for carrying out azimuthal stabilisation, wherein said set point valve is identical to the bearing of the vehicle carrying said transducer array (1) quantized with m+p digits; every scanning revolution of the transducer array the discrete control signals (P1 . . . PN) applied to the multiplex systems (3) and the interval between the fixed (F2) and variable (F1) frequencies applied respectively to said samplers (6, 4), being thus modified as a function of variations in the bearing during a revolution.
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) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |