US3821646A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scatter communication system
Assignee: Raytheon Co
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Filing: 1972-02-25
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Granted: 1974-06-28
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Expires: 1992-02-25
Abstract
Abstract A scatter communication system which utilizes a scattering medium whose time variations of index of refraction within the medium are random and slow compared to the characteristic times of the radiation and the propagation time. The system is designed to provide a means of eliminating the deep fading from the mean value of signal strength encountered in a tropospheric and ionospheric scatter communication systems. By very rapidly scanning the transmitting antenna beam at a rate at least equal to twice the highest information frequency on the carrier, short term fading on the order of less than one minute is eliminated.
Inventors
- 👤 W Bickford
- 👤 H Rowland
- 👤 C Tsao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:38
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/22
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
179 words
A scatter communication system comprising: a transmitter including a scanned antenna for transmitting a signal, individual portions of said transmitted signal being scanned by said antenna in different directions to traverse a different Transmission path for each of said portions and wherein said scanning rate is at least equal to twice the highest information frequency on said transmitted signal; a receiver including an antenna for receiving the portions of said transmitted signal, each of said transmission paths beginning at said transmitter and terminating at said receiver; scan control means coupled to said transmitter for altering said transmission paths for sequential ones of said portions of said transmitted signal; means coupled to said receiver for generating a plurality of tones each of which is representative of the phase of a corresponding individual portion of said received signal; means for beating said plurality of generated tones with their corresponding individual signal portions; and filter means coupled to said beating means, the bandwidth of said filter means being matched to the information rate of said transmitted signal for reconstructing said transmitted signal.
Claim 2
Dependent Claim
179 words
A scatter communication system comprising: a transmitter including a scanned antenna for transmitting a signal, individual portions of said transmitted signal being scanned by said antenna in different directions to traverse a different Transmission path for each of said portions and wherein said scanning rate is at least equal to twice the highest information frequency on said transmitted signal; a receiver including an antenna for receiving the portions of said transmitted signal, each of said transmission paths beginning at said transmitter and terminating at said receiver; scan control means coupled to said transmitter for altering said transmission paths for sequential ones of said portions of said transmitted signal; means coupled to said receiver for generating a plurality of tones each of which is representative of the phase of a corresponding individual portion of said received signal; means for beating said plurality of generated tones with their corresponding individual signal portions; and filter means coupled to said beating means, the bandwidth of said filter means being matched to the information rate of said transmitted signal for reconstructing said transmitted signal.
Claim 3
Independent Claim
117 words
A method for eliminating the effects of short term fading from the mean value of a signal in scatter communication systems, said method comprising the steps of: transmitting a beam of said signal; rapidly scanning said transmitted beam of said signal at a rate equal to at least twice the highest information frequency of said signal to transmit portions of said signal over different paths; receiving the transmitted signal portions; sequentially selecting said received portions of said transmitted signal; generating a plurality of tones representing the corresponding phases of said selected signal portions; beating individual ones of said tones with corresponding ones of said received signal portions to provide a resultant signal; and filtering the resultant signal.
Claim 4
Independent Claim
117 words
A method for eliminating the effects of short term fading from the mean value of a signal in scatter communication systems, said method comprising the steps of: transmitting a beam of said signal; rapidly scanning said transmitted beam of said signal at a rate equal to at least twice the highest information frequency of said signal to transmit portions of said signal over different paths; receiving the transmitted signal portions; sequentially selecting said received portions of said transmitted signal; generating a plurality of tones representing the corresponding phases of said selected signal portions; beating individual ones of said tones with corresponding ones of said received signal portions to provide a resultant signal; and filtering the resultant signal.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |