US4259741A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Satellite relay system
Assignee: NTT Inc
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Filing: 1979-03-05
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Granted: 1981-03-31
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Expires: 1999-03-05
Abstract
Abstract A satellite relay system for Time Division Multiple Access (TDMA) utilizing a beam scanning technique has been found. According to the present invention a plurality of antennas each relating to the corresponding earth station have a narrow spot beam with sharp directivity. Each of the up-link bursts (a signal from an earth station to a satellite) is simply combined, and a single-channel TDMA signal is obtained. Said TDMA signal is then divided into a plurality of signals by a power divider after frequency conversion. Each of said signals is processed by a variable phase shifter, the output of which is applied to a power amplifier. A 2n-port directional coupler having n number of input terminals and n number of output terminals is provided and each of said input terminals is connected to the output of the corresponding power amplifier. Each of the output signals of the 2n-port directional coupler provides a down-link burst and is connected to the corresponding transmission antenna which has a sharp directivity covering only a single specific earth station. The 2n-port directional coupler is composed of a plurality of couplers or hybrid circuits.
Inventors
- 👤 Makoto Kawai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:03
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/36; H04; H04B; H04B7/00; H04B7/14; H04B7/15; H04B7/204; H04B7/2046
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
224 words
A TDMA satellite relay system comprising: a power divider means having a single input and n output terminals where n is an integer, said power divider means receiving a TDMA input signal having a plurality of non-overlapped burst signals relating to a different earth station and distributing the power in said inut signal to each of said output terminals, n phase shifters, each coupled to a corresponding output of said power divider, n power amplifiers, each coupled to a corresponding output of said phase shifters, a 2n-port directional coupler means consisting of n number of input terminals, each coupled to a corresponding power amplifier, n number of output terminals, and a plurality of couplers between said input terminals and said output terminals wherein the input power of any one of the input terminals is equally distributed to all the output terminals, n number of transmission antennas, each coupled to a corresponding output of said 2n-port directional coupler means, and each antenna having a narrow spot beam covering a single specific earth station with no overlap therebetween, and a phaseshifter control for controlling said phase shifters such that each burst signal in the TDMA signal is connected to a corresponding antenna on a time divisional basis through said 2n-port directional coupler means wherein said phase shifter control synchronizes said phase shifters with said burst signal.
Claim 2
Dependent Claim
224 words
A TDMA satellite relay system comprising: a power divider means having a single input and n output terminals where n is an integer, said power divider means receiving a TDMA input signal having a plurality of non-overlapped burst signals relating to a different earth station and distributing the power in said inut signal to each of said output terminals, n phase shifters, each coupled to a corresponding output of said power divider, n power amplifiers, each coupled to a corresponding output of said phase shifters, a 2n-port directional coupler means consisting of n number of input terminals, each coupled to a corresponding power amplifier, n number of output terminals, and a plurality of couplers between said input terminals and said output terminals wherein the input power of any one of the input terminals is equally distributed to all the output terminals, n number of transmission antennas, each coupled to a corresponding output of said 2n-port directional coupler means, and each antenna having a narrow spot beam covering a single specific earth station with no overlap therebetween, and a phaseshifter control for controlling said phase shifters such that each burst signal in the TDMA signal is connected to a corresponding antenna on a time divisional basis through said 2n-port directional coupler means wherein said phase shifter control synchronizes said phase shifters with said burst signal.
Claim 3
Dependent Claim
75 words
A TDMA satellite relay system according to claim 1 further comprising n number of reception antennas, each having a narrow spot beam covering a single specific earth station, n number of amplifiers each coupled to a corresponding reception antenna, a power combiner for combining all the outputs of said amplifiers, and a frequency mixer for converting the frequency of said power combiner and providing the converted signal to the input of said power divider means.
Claim 4
Dependent Claim
22 words
A TDMA satellite relay system according to claim 2, wherein a transmission antenna functions as a reception antenna through an antenna multiplexer.
Claim 5
Dependent Claim
19 words
A TDMA satellite relay system according to claim 3 including a single reflection mirror common to all said antennas.
Claim 6
Dependent Claim
25 words
A TDMA satellite relay system according to claim 1 wherein said couplers of said 2n-port directional coupler means includes a plurality of 90° hybrid circuits.
Claim 7
Dependent Claim
45 words
A TDMA satellite relay system according to claim 1 wherein said n number of transmission antennas relates to a vertically polarized wave and a horizontally polarized wave, wherein said vertically and horizontally polarized waves do not cover a specific earth station at the same time.
Claim 8
Dependent Claim
20 words
A TDMA satellite relay system according to claim 1 wherein each of said phase shifters is a one-bit phase shifter.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-30 | 1984-09-29 | 1985-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-30 | 1988-09-29 | 1989-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-30 | 1992-09-29 | 1993-03-31 | $7700.00 | Window Closed / Lapsed |