US3728729A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radio navigation beacon including antenna element commutation
Assignee: International Standard Electric Corp
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Filing: 1971-12-22
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Granted: 1973-04-17
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Expires: 1991-12-22
Abstract
Abstract A radio navigation beacon system of the Doppler type having a simplified antenna arrangement. A main array employing 30 array elements spaced at four wavelengths and an auxiliary or reference array comprising 12 reference antenna elements spaced at onethird wavelength, are employed. A source of radio frequency energy is commutated to the separate radiator elements in order to simulate unidirectional or bidirectional constant velocity motion of the source. Navigational information is derived from this ground beacon arrangement by a receiving station as, for example, in an approaching aircraft on the basis that the Doppler shift of frequency observed at the receiving station is proportional to the cosine of the angle of reception with respect to the operating centerline of the system. Means are included for commutating the reference frequency to each reference antenna element, in turn, during the period that each main array element is radiating.
Inventors
- 👤 F Overbury
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:03
CPC Classifications
G; G01; G01S; G01S1/00; G01S1/02; G01S1/08; G01S1/38; G01S1/40
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
202 words
In a radio navigation beacon system which simulates motion by electrical sequencing of antenna elements to generate an apparent Doppler frequency component at a receiving station, the combination comprising: a first source of radio frequency energy of a first frequency; a first antenna array including a plurality of equally spaced antenna radiating elements disposed in a line at an angle with respect to the ideal navigational path; first commutating means for successively switching the output of said first source to each of said radiating elements of said first array according to a predetermined pattern; a second antenna array including a plurality of equally spaced antenna radiating elements disposed in a line at an angle with respect to said ideal navigational path, said second array having an overall length equal to the spacing between adjacent elements of said first array; a second source of radio frequency energy of a second frequency different from said frequency; and second commutating means for successively switching the output of said second source of radio frequency energy to each of said radiating elements of said second array in succession during the time of energization of each of said first array elements by said energy of said first frequency.
Claim 2
Dependent Claim
202 words
In a radio navigation beacon system which simulates motion by electrical sequencing of antenna elements to generate an apparent Doppler frequency component at a receiving station, the combination comprising: a first source of radio frequency energy of a first frequency; a first antenna array including a plurality of equally spaced antenna radiating elements disposed in a line at an angle with respect to the ideal navigational path; first commutating means for successively switching the output of said first source to each of said radiating elements of said first array according to a predetermined pattern; a second antenna array including a plurality of equally spaced antenna radiating elements disposed in a line at an angle with respect to said ideal navigational path, said second array having an overall length equal to the spacing between adjacent elements of said first array; a second source of radio frequency energy of a second frequency different from said frequency; and second commutating means for successively switching the output of said second source of radio frequency energy to each of said radiating elements of said second array in succession during the time of energization of each of said first array elements by said energy of said first frequency.
Claim 3
Dependent Claim
22 words
Apparatus according to claim 1 in which the elements of said first and second arrays are disposed substantially on the same line.
Claim 4
Dependent Claim
51 words
Apparatus according to claim 2 in which said second commutating means is adapted to switch said energy of said second frequency successively among said elements of said second array in the opposite direction along said same line as the direction of switching provided by said first commutating means at any time.
Claim 5
Dependent Claim
35 words
Apparatus according to claim 3 in which said angle of said same line along which said first and second arrays are disposed makes an angle of substantially 90* with respect to said ideal navigational path.
Claim 6
Dependent Claim
53 words
Apparatus according to claim 3 in which said first array is identified as the primary array and said second array is identified as the reference array, in which said primary array is defined as having an overall length which is an integral number of wavelength times the overall length of said reference array.
Claim 7
Dependent Claim
51 words
Apparatus according to claim 5 in which the elements of said primary array are spaced four wavelengths apart and the elements of said reference array are spaced one-third wavelength apart, whereby said first and second commutating means operate to produce discrete radiated energy path length changes in steps of one-third wavelength.
Claim 8
Dependent Claim
20 words
Apparatus according to claim 6 in which said primary array comprises 30 elements and said reference array comprises 12 elements.
Claim 9
Dependent Claim
49 words
Apparatus according to claim 5 in which said second frequency is defined as being different from said first frequency by an amount comparable to the Doppler frequencies produced by said commutators, said difference between said first and second frequencies being a small percentage of said first or second frequency.
Claim 10
Dependent Claim
30 words
Apparatus according to claim 8 in which said frequency difference is on the order of 20 KHz, whereas said first and second frequencies are on the order of 1.0 GHz.
Claim 11
Dependent Claim
43 words
Apparatus according to claim 4 in which means are included for supporting both said primary and reference arrays along said same Line, said reference array being spaced a predetermined distance along said same line from one end radiating element of said primary array.
References Cited (Backward Citations)
US3670337A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |