EP0270112A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Radio transmitter-receiver system for increasing or decreasing communication channels
Assignee: Fujitsu Ltd
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Filing: 1987-12-03
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Granted: —
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Expires: 2007-12-03
Abstract
Abstract The radio transmitter-receiver system for increasing or decreasing communication channels comprises radio transmitter-receivers (11, 11A, 12, 12A, 13, 13A) each including a separated intermediate frequency portion for modulation and demodulation and a separated microwave portion and having a multiplexer (78) and a divider (90) therebetween. Local oscillators (75) in the intermediate frequency portion have a variable frequency function and the operating frequency of the intermediate frequency portion can be easily changed. The intermediate frequency portions are connected to the microwave portions through the multiplexer (78) or the divider (90) and the frequency of the microwave to be communicated is easily changed. Thus, an increase or decrease of the communication channels is possible at a low cost.
Inventors
- 👤 Susumu Sasaki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 16:25
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/74
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
229 words
A radio transmitter-receiver system for increasing or decreasing communication channels comprising: - a plurality of antennas (61) for receiving input RF signals and for transmitting output RF signals, - a plurality of transmitter-receivers (11, 11A; 12, 12A; 13, 13A) provided with RF portions and an IF portion, said RF portions receiving RF signals from said antennas (61) and supplying RF outputs to said antennas (61), an intermediate frequency from said IF portions and a radio frequency from said antennas (61) at said RF portions being converted to a radio frequency to said antennas (61) and to an intermediate frequency to said IF portions, respectively, a baseband input and an intermediate frequency from said RF portions at said IF portions being converted to an intermediate frequency to said RF portions and to a baseband output, respectively, and said IF portions being provided with local oscillators (75) generating variable frequencies, - IF multiplexers (78) and IF dividers (90) provided between said RF portions and said IF portions, said IF multiplexers (78) receiving outputs from a plurality of IF portions and supplying an output to said RF portions, said IF dividers (90) receiving an output of said RF portions and supplying outputs to a plurality of IF portions, and - a plurality of communication lines, each having a different frequency, provided between said plurality of antennas (61) to form a communication network.
Claim 2
Dependent Claim
229 words
A radio transmitter-receiver system for increasing or decreasing communication channels comprising: - a plurality of antennas (61) for receiving input RF signals and for transmitting output RF signals, - a plurality of transmitter-receivers (11, 11A; 12, 12A; 13, 13A) provided with RF portions and an IF portion, said RF portions receiving RF signals from said antennas (61) and supplying RF outputs to said antennas (61), an intermediate frequency from said IF portions and a radio frequency from said antennas (61) at said RF portions being converted to a radio frequency to said antennas (61) and to an intermediate frequency to said IF portions, respectively, a baseband input and an intermediate frequency from said RF portions at said IF portions being converted to an intermediate frequency to said RF portions and to a baseband output, respectively, and said IF portions being provided with local oscillators (75) generating variable frequencies, - IF multiplexers (78) and IF dividers (90) provided between said RF portions and said IF portions, said IF multiplexers (78) receiving outputs from a plurality of IF portions and supplying an output to said RF portions, said IF dividers (90) receiving an output of said RF portions and supplying outputs to a plurality of IF portions, and - a plurality of communication lines, each having a different frequency, provided between said plurality of antennas (61) to form a communication network.
Claim 3
Dependent Claim
62 words
The system as set forth in claim 1, wherein when a communication line failure occurs, a frequency of a local oscillator (75) in said IF portion of an associated transmitter-receiver is changed, the output of said IF portion is connected to said IF multiplexer (78) and said IF divider (90) belonging to another communication line, and the failed communication line is by-passed.
Claim 4
Dependent Claim
19 words
The system as set forth in claim 1 or 2, wherein at least one transmitter-receiver is a standby apparatus.
Claim 5
Dependent Claim
190 words
The system as set forth in claim 1, wherein each of said RF portions and IF portions is provided with a transmitter portion and a receiver portion, a transmitter portion of each of said RF portions comprises a first RF oscillator (80), a first RF mixer (79) for mixing the outputs of said IF multiplexer (78) and the first RF oscillator (80), the transmitter portion of said IF portion comprises the local oscillator (80), a modulator (73) for receiving a baseband input signal, and a first IF mixer (74) for mixing outputs of the modulator (73) and the local oscillator (80), a receiver portion of said RF portion comprises a second RF oscillator (87) and a second RF mixer (86) for mixing the RF input and the output of the second RF oscillator (87), and a receiver portion of said IF portion comprises another local oscillator, a second IF mixer (91) for mixing the IF output from said IF divider (90) and the output of the another local oscillator, and a demodulator (95) for receiving the output of the second IF mixer (91) and for outputting the baseband signal output.
Claim 6
Dependent Claim
57 words
The system as set forth in claim 1, wherein when a communication line failure occurs, an output of the associated one of said IF portions is connected to said IF multiplexer (78) and said IF divider (90) belonging to another communication line, and the failed communication line is by-passed using the same frequency as the failed line.
References Cited (Backward Citations)
No citation records indexed.
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