Patent US3715664A successfully refreshed from Google Patents.
US3715664A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of repeating rf-borne signal across an earth barrier
Assignee: United States Department of the Army
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Filing: 1971-02-12
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Granted: 1973-02-06
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Expires: 1991-02-12
Abstract
Abstract A method of relaying VHF in mountainous terrain that includes planting a receiver and a transmitter, that operate at the same carrier frequency, on opposite sides of a mount such that the mountain between them shields the receiver from rf radiated by the transmitter, and transferring intelligence on the rf detected by the receiver through the earth to the transmitter by means of a magnetic or seismic link. The magnetic link can transfer audio band frequency while the seismic link can transfer mark-space coded intelligence.
Inventors
- 👤 K Ikrath
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:29
CPC Classifications
H; H04; H04B; H04B13/00; H04B13/02
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
167 words
A method of relaying modulated rf in hilly, mountainous or scarred terrain comprising the steps of intercepting the rf in the atmosphere at a first site backed by a rise in the terrain, detecting the modulation of the intercepted rf, generating LF electrical current and modulating the LF electrical current corresponding to the detected modulation on the intercepted rf, converting the LF electrical current at the first site to earth-penetrating energy of corresponding waveform, sensing the earth-penetrating LF energy at a second site separated from the first site by the rise in terrain where the rise in terrain between the two sites blocks transfer of rf between the two sites, detecting at the second site the modulation on the sensed earth-penetrating LF energy, generating rf of the same frequency at the second site and modulating the rf in accordance with the modulation detected at the second site and radiating the modulated rf from the second site at higher intensity than the rf intercepted at the first site.
Claim 2
Independent Claim
167 words
A method of relaying modulated rf in hilly, mountainous or scarred terrain comprising the steps of intercepting the rf in the atmosphere at a first site backed by a rise in the terrain, detecting the modulation of the intercepted rf, generating LF electrical current and modulating the LF electrical current corresponding to the detected modulation on the intercepted rf, converting the LF electrical current at the first site to earth-penetrating energy of corresponding waveform, sensing the earth-penetrating LF energy at a second site separated from the first site by the rise in terrain where the rise in terrain between the two sites blocks transfer of rf between the two sites, detecting at the second site the modulation on the sensed earth-penetrating LF energy, generating rf of the same frequency at the second site and modulating the rf in accordance with the modulation detected at the second site and radiating the modulated rf from the second site at higher intensity than the rf intercepted at the first site.
Claim 3
Independent Claim
167 words
A method of relaying modulated rf in hilly, mountainous or scarred terrain comprising the steps of intercepting the rf in the atmosphere at a first site backed by a rise in the terrain, detecting the modulation of the intercepted rf, generating LF electrical current and modulating the LF electrical current corresponding to the detected modulation on the intercepted rf, converting the LF electrical current at the first site to earthpenetrating energy of corresponding waveform, sensing the earth-penetrating LF energy at a second site separated from the first site by the rise in terrain where the rise in terrain between the two sites blocks transfer of rf between the two sites, detecting at the second site the modulation on the sensed earthpenetrating LF energy, generating rf of the same frequency at the second site and modulating the rf in accordance with the modulation detected at the second site and radiating the modulated rf from the second site at higher intensity than the rf intercepted at the first site.
Claim 4
Independent Claim
167 words
A method of relaying modulated rf in hilly, mountainous or scarred terrain comprising the steps of intercepting the rf in the atmosphere at a first site backed by a rise in the terrain, detecting the modulation of the intercepted rf, generating LF electrical current and modulating the LF electrical current corresponding to the detected modulation on the intercepted rf, converting the LF electrical current at the first site to earthpenetrating energy of corresponding waveform, sensing the earth-penetrating LF energy at a second site separated from the first site by the rise in terrain where the rise in terrain between the two sites blocks transfer of rf between the two sites, detecting at the second site the modulation on the sensed earthpenetrating LF energy, generating rf of the same frequency at the second site and modulating the rf in accordance with the modulation detected at the second site and radiating the modulated rf from the second site at higher intensity than the rf intercepted at the first site.
Claim 5
Dependent Claim
22 words
The method of relaying rf in hilly, mountainous or scarred terrain as defined in claim 1 wherein the earth-penetrating energy is magnetic.
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) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |