Patent US4890110A successfully refreshed from Google Patents.
US4890110A
Expired / Lapsed
US
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Microwave landing system
Assignee: NEC Corp
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Filing: 1988-12-30
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Granted: 1989-12-26
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Expires: 2008-12-30
Abstract
Abstract A microwave landing system in which a beam scanning antenna is provided with an amplifying function to constitute an active array, a traditional power amplifier and the like are omitted to enhance the reliability of operation. The outputs of phase shifters each being associated with a respective one of radiating elements are connected to 1/2 dividers each having p-i-n diodes at opposite output terminals thereof, and the p-i-n diodes of each 1/2 divider are turned on and off alternately. Output signals are fed to radiating elements and a multiplexer with a minimum of loss.
Inventors
- 👤 Yoshihiko Kuwahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:40
CPC Classifications
G; G01; G01S; G01S1/00; G01S1/02; G01S1/08; G01S1/44; G01S1/54; G01S1/56
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
231 words
A microwave landing system for feeding predetermined power to an auxiliary antenna, comprising: a power divider for dividing power in a distribution ratio which is associated with n radiating elements of a beam scanning antenna; n phase shifters individually associated with said n radiating elements for providing fractions of the divided power with phases for effecting beam scanning; n variable attenuators individually associated said n phase shifters for providing outputs of said phase shifters with attenuations of predetermined characteristics which are variable depending upon whether or not a beam scanning timing is reached; n power amplifiers individually associated with said n variable attenuators for amplifying outputs of said variable attenuators to a predetermined level; n 1/2 dividers individually associated with said n power amplifiers for dividing outputs of said power amplifiers into two and each feeding one of resulting two outputs to said radiating element associated with said 1/2 divider, said 1/2 dividers each comprising two p-i-n diodes individually connected between opposite output terminals and ground and turning off said p-i-n diodes connected to said radiating element and turning on the other p-i-n diode at a beam scanning timing; and a power combiner for combining said other output of said n 1/2 dividers being not connected to said radiating elements in a predetermined format and delivering a resulting combined signal to an auxiliary antenna located outside of said n radiating elements.
Claim 2
Dependent Claim
231 words
A microwave landing system for feeding predetermined power to an auxiliary antenna, comprising: a power divider for dividing power in a distribution ratio which is associated with n radiating elements of a beam scanning antenna; n phase shifters individually associated with said n radiating elements for providing fractions of the divided power with phases for effecting beam scanning; n variable attenuators individually associated said n phase shifters for providing outputs of said phase shifters with attenuations of predetermined characteristics which are variable depending upon whether or not a beam scanning timing is reached; n power amplifiers individually associated with said n variable attenuators for amplifying outputs of said variable attenuators to a predetermined level; n 1/2 dividers individually associated with said n power amplifiers for dividing outputs of said power amplifiers into two and each feeding one of resulting two outputs to said radiating element associated with said 1/2 divider, said 1/2 dividers each comprising two p-i-n diodes individually connected between opposite output terminals and ground and turning off said p-i-n diodes connected to said radiating element and turning on the other p-i-n diode at a beam scanning timing; and a power combiner for combining said other output of said n 1/2 dividers being not connected to said radiating elements in a predetermined format and delivering a resulting combined signal to an auxiliary antenna located outside of said n radiating elements.
Claim 3
Dependent Claim
37 words
A microwave landing system as claimed in claim 1, wherein said variable attenuators each comprises a p-i-n diode switch and fixed attenuators individually connected to an input side and an output side of said p-i-n diode switch.
Claim 4
Dependent Claim
28 words
A microwave landing system as claimed in claim 2, wherein a multiplicity of said variable attenuators each comprising said p-i-n diode switch and said fixed attenuators are cascaded.
References Cited (Backward Citations)
US4837580A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-25 | 1993-06-26 | 1993-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-25 | 1997-06-26 | 1997-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-25 | 2001-06-26 | 2001-12-26 | $7700.00 | Window Closed / Lapsed |