Patent US3750020A successfully refreshed from Google Patents.
US3750020A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radio communication transmission system for vehicles
Assignee: Individual
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Filing: 1971-07-12
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Granted: 1973-07-31
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Expires: 1991-07-12
Abstract
Abstract A radio communication transmission system for moving vehicles following a track wherein an intermediate frequency communication signal is transmitted on a leaky coaxial cable at a low loss from a ground station. This signal is periodically amplified, if required, to compensate for attenuation, and is also periodically frequency converted into a radio frequency signal which is transmitted along with the aforesaid intermediate frequency signal on the same leaky coaxial cable for uniform leakage therealong for coupling to an antenna on a vehicle traveling adjacent the leaky coaxial cable. A transmitter is provided on the moving vehicle and transmits a second radio frequency signal from the vehicle to couple the signal to the leaky coaxial cable for transmission thereon. This second radio frequency signal is then frequency converted to a second intermediate frequency signal for transmission at a low loss thereafter on the same leaky coaxial cable to a ground station for reception.
Inventors
- 👤 T Nagao
- 👤 M Sasada
- 👤 M Nakagawa
- 👤 T Baba
- 👤 K Shibuya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:55
CPC Classifications
H; H04; H04B; H04B5/00; H04B5/20; H04B5/28
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
233 words
A radio communication transmission system for moving vehicles following a track comprising a leaky coaxial cable installed in parallel along a track for a moving vehicle, repeaters interposed in said cable at predetermined locations, transmission means connected to said leaky coaxial cable to transmit thereon a signal from a ground station along said leaky coaxial cable at a low loss from repeater to repeater at a first intermediate frequency, amplification means at each repeater responsive to said first intermediate frequency signal to retransmit said first intermediate frequency signal at a low loss further along said leaky coaxial cable, a frequency converter at each repeater responsive to said first intermediate frequency signal to frequency convert a sample of said first intermediate frequency signal into a first radio frequency signal and to transmit said first radio frequency signal further along said leaky coaxial cable at a uniform leakage for coupling with a receiving antenna on a vehicle on the track, a transmitter with a transmission antenna on a vehicle on the track for the transmission of a second radio frequency signal which will couple with said leaky coaxial cable, said converter being operable to frequency convert said second radio frequency signal to a second intermediate frequency signal and to transmit said second intermediate frequency signal at a low loss on said leaky coaxial cable from repeater to repeater for eventual reception by a ground station.
Claim 2
Dependent Claim
233 words
A radio communication transmission system for moving vehicles following a track comprising a leaky coaxial cable installed in parallel along a track for a moving vehicle, repeaters interposed in said cable at predetermined locations, transmission means connected to said leaky coaxial cable to transmit thereon a signal from a ground station along said leaky coaxial cable at a low loss from repeater to repeater at a first intermediate frequency, amplification means at each repeater responsive to said first intermediate frequency signal to retransmit said first intermediate frequency signal at a low loss further along said leaky coaxial cable, a frequency converter at each repeater responsive to said first intermediate frequency signal to frequency convert a sample of said first intermediate frequency signal into a first radio frequency signal and to transmit said first radio frequency signal further along said leaky coaxial cable at a uniform leakage for coupling with a receiving antenna on a vehicle on the track, a transmitter with a transmission antenna on a vehicle on the track for the transmission of a second radio frequency signal which will couple with said leaky coaxial cable, said converter being operable to frequency convert said second radio frequency signal to a second intermediate frequency signal and to transmit said second intermediate frequency signal at a low loss on said leaky coaxial cable from repeater to repeater for eventual reception by a ground station.
Claim 3
Independent Claim
107 words
The method of transmitting communication signals between a moving vehicle and a ground station comprising the steps of transmitting an intermediate frequency communication signal on a leaky coaxial cable at a low loss, amplifying said inteRmediate frequency signal and retransmitting said intermediate frequency signal at predetermined locations, frequency converting a sample of said signal intermediate frequency into a radio frequency signal and transmitting said radio frequency signal along with said intermediate frequency signal on the same leaky coaxial cable a said predetermined locations for uniform leakage therealong of said radio frequency signal for coupling to an antenna on a vehicle traveling adjacent to said leaky coaxial cable.
Claim 4
Independent Claim
107 words
The method of transmitting communication signals between a moving vehicle and a ground station comprising the steps of transmitting an intermediate frequency communication signal on a leaky coaxial cable at a low loss, amplifying said inteRmediate frequency signal and retransmitting said intermediate frequency signal at predetermined locations, frequency converting a sample of said signal intermediate frequency into a radio frequency signal and transmitting said radio frequency signal along with said intermediate frequency signal on the same leaky coaxial cable a said predetermined locations for uniform leakage therealong of said radio frequency signal for coupling to an antenna on a vehicle traveling adjacent to said leaky coaxial cable.
Claim 5
Dependent Claim
67 words
The method of claim 2 characterized by the steps of transmitting a second radio frequency signal from a vehicle moving adjacent the leaky coaxial cable to couple the same thereto for transmission thereon, and frequency converting said second radio frequency signal on said leaky coaxial cable to a second intermediate frequency signal for transmission at a low loss on said leaky coaxial cable to a ground station.
References Cited (Backward Citations)
US2509218A
Cited
US3278850A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |