US3887922A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Instrument landing system with microwave course pattern transmission
Assignee: International Standard Electric Corp
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Filing: 1974-01-23
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Granted: 1975-06-03
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Expires: 1994-01-23
Abstract
Abstract A combined microwave and standard ILS system. Course information for at least one of the localizer and glide-slope functions is transmitted in the microwave frequency region, down-converted in the air and mixed into the clearance channels where it overrides standard clearance signals in substantially the same way as with standard ILS course signals on a landing approach. The system is compatible with existing airborne ILS equipment.
Inventors
- 👤 Gunter Hofgen
- 👤 Werner Poschadel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:52
CPC Classifications
G; G01; G01S; G01S1/00; G01S1/02; G01S1/08; G01S1/14
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
171 words
An instrument landing system of the two-carrier type including ground based localizer and glide-slope signal transmitting means, each generating a clearance radiation pattern and a course radiation pattern, the carrier frequencies for said localizer and glide-slope clearance patterns being in the VHF and UHF regions, respectively; said system including an airborne receiver for determining deviations from a desired landing path by comparison of relative amplitudes of 90Hz and 150Hz modulation on a carrier, comprising the combination of: ground means for generating and radiating a course radiation pattern for at least one of said localizer and glide-slope functions in the microwave frequency region; and airborne means including a microwave receiving antenna and a converter responsive thereto for converting said microwave radiation into the frequency domain of the corresponding clearance channel, and also including means for mixing said converted microwave radiation with corresponding lower carrier frequency received clearance radiation, thereby to provide for a capture effect such that said airborne means will automatically respond to ground radiations with or without said microwave radiation.
Claim 2
Dependent Claim
171 words
An instrument landing system of the two-carrier type including ground based localizer and glide-slope signal transmitting means, each generating a clearance radiation pattern and a course radiation pattern, the carrier frequencies for said localizer and glide-slope clearance patterns being in the VHF and UHF regions, respectively; said system including an airborne receiver for determining deviations from a desired landing path by comparison of relative amplitudes of 90Hz and 150Hz modulation on a carrier, comprising the combination of: ground means for generating and radiating a course radiation pattern for at least one of said localizer and glide-slope functions in the microwave frequency region; and airborne means including a microwave receiving antenna and a converter responsive thereto for converting said microwave radiation into the frequency domain of the corresponding clearance channel, and also including means for mixing said converted microwave radiation with corresponding lower carrier frequency received clearance radiation, thereby to provide for a capture effect such that said airborne means will automatically respond to ground radiations with or without said microwave radiation.
Claim 3
Dependent Claim
171 words
An instrument landing system of the two-carrier type including ground based localizer and glide-slope signal transmitting means, each generating a clearance radiation pattern and a course radiation pattern, the carrier frequencies for said localizer and glide-slope clearance patterns being in the VHF and UHF regions, respectively; said system including an airborne receiver for determining deviations from a desired landing path by comparison of relative amplitudes of 90Hz and 150Hz modulation on a carrier, comprising the combination of: ground means for generating and radiating a course radiation pattern for at least one of said localizer and glide-slope functions in the microwave frequency region; and airborne means including a microwave receiving antenna and a converter responsive thereto for converting said microwave radiation into the frequency domain of the corresponding clearance channel, and also including means for mixing said converted microwave radiation with corresponding lower carrier frequency received clearance radiation, thereby to provide for a capture effect such that said airborne means will automatically respond to ground radiations with or without said microwave radiation.
Claim 4
Dependent Claim
171 words
An instrument landing system of the two-carrier type including ground based localizer and glide-slope signal transmitting means, each generating a clearance radiation pattern and a course radiation pattern, the carrier frequencies for said localizer and glide-slope clearance patterns being in the VHF and UHF regions, respectively; said system including an airborne receiver for determining deviations from a desired landing path by comparison of relative amplitudes of 90Hz and 150Hz modulation on a carrier, comprising the combination of: ground means for generating and radiating a course radiation pattern for at least one of said localizer and glide-slope functions in the microwave frequency region; and airborne means including a microwave receiving antenna and a converter responsive thereto for converting said microwave radiation into the frequency domain of the corresponding clearance channel, and also including means for mixing said converted microwave radiation with corresponding lower carrier frequency received clearance radiation, thereby to provide for a capture effect such that said airborne means will automatically respond to ground radiations with or without said microwave radiation.
Claim 5
Dependent Claim
45 words
Apparatus according to claim 1 comprising an oscillator within said ground based transmitting means, and means for transmitting a microwave signal to said converter in said airborne receiver as a local oscillator signal, thereby to provide a ground generated frequency reference for said airborne receiver.
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) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |