Patent US5574986A successfully refreshed from Google Patents.
US5574986A
Expired / Lapsed
US
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Telecommunication system, and a first station, a second station, and a transceiver for use in such a system
Assignee: US Philips Corp
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Filing: 1994-11-16
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Granted: 1996-11-12
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Expires: 2014-11-16
Abstract
Abstract In a cordless telephony system such as CT1 or CT1 + there is only a small separation between the transmit and receive frequencies. Consequently, when transceivers with so-called dual frequency synthesizers in a single package are used for the respective receiver and transmitter branches, crosstalk via the synthesizer package occurs between the two branches. To suppress such crosstalk, in accordance with the invention low pass and high pass filters are included in the respective paths from the receiver and transmitter branches through the dual frequency synthesizers.
Inventors
- 👤 Carel H. D. Mobach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:34
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/72; H04M1/725; H04M1/72502; H04B; H04B1/00; H04B1/38; H04B1/40
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
162 words
A telecommunication system which includes a first station having a first transceiver and a second station having a second transceiver, the first and second stations being arranged for radio communication with each other; at least the first transceiver comprising: a receiver branch with a first phase-lock-loop for providing a first local oscillator signal (LO1), and a transmitter branch with a second phase-lock-loop for providing a second local oscillator signal (LO2); the first and second phase-lock-loops respectively comprising first and second synthesizers which are coupled to each other; the receiver branch comprising a first frequency multiplier for multiplying the first local oscillator signal (LO1) by a first integer greater than one, the multiplied signal being produced at an output of the first multiplier which is coupled to an rf-path in the receiver branch; and a first filter in the phase-lock-loop of one of said branches for suppressing signals which reach said one branch from the other branch via said first and second synthesizers.
Claim 2
Dependent Claim
162 words
A telecommunication system which includes a first station having a first transceiver and a second station having a second transceiver, the first and second stations being arranged for radio communication with each other; at least the first transceiver comprising: a receiver branch with a first phase-lock-loop for providing a first local oscillator signal (LO1), and a transmitter branch with a second phase-lock-loop for providing a second local oscillator signal (LO2); the first and second phase-lock-loops respectively comprising first and second synthesizers which are coupled to each other; the receiver branch comprising a first frequency multiplier for multiplying the first local oscillator signal (LO1) by a first integer greater than one, the multiplied signal being produced at an output of the first multiplier which is coupled to an rf-path in the receiver branch; and a first filter in the phase-lock-loop of one of said branches for suppressing signals which reach said one branch from the other branch via said first and second synthesizers.
Claim 3
Dependent Claim
32 words
A telecommunication system as claimed in claim 1, wherein said first filter is a low pass filter and is coupled between an input of the first frequency multiplier and the first synthesizer.
Claim 4
Dependent Claim
32 words
A telecommunication system as claimed in claim 1, wherein the first filter is a high pass filter and is coupled between the output of the first frequency multiplier and the first synthesizer.
Claim 5
Dependent Claim
144 words
A telecommunication system as claimed in claim 1, wherein the first filter is in the phase-lock-loop of the receiver branch, and the transmitter branch further comprises: a second frequency multiplier for multiplying the second local oscillator signal (LO2) by a second integer value greater than one, the multiplied signal being produced at an output of the second frequency multiplier which is coupled to an rf-path in the transmitter branch; and a second filter in the phase-lock-loop of the transmitter branch, said second filter (i) being a high pass filter which is coupled between the output of the second frequency multiplier and the second synthesizer, when said first filter is a low pass filter, and (ii) being a low pass filter which is coupled between an input of the second frequency multiplier and the second synthesizer, when said first filter is a high pass filter.
Claim 6
Dependent Claim
150 words
A station for use in a telecommunication system having a plurality of stations which are arranged for radio communication with each other, said station including a transceiver comprising: a receiver branch with a first phase-lock-loop for providing a first local oscillator signal (LO1), and a transmitter branch with a second phase-lock-loop for providing a second local oscillator signal (LO2); the first and second phase-lock-loops respectively comprising first and second synthesizers which are coupled to each other; the receiver branch comprising a first frequency multiplier for multiplying the first local oscillator signal (LO1) by a first integer greater than one, the multiplied signal being produced at an output of the first multiplier which is coupled to an rf-path in the receiver branch; and a filter in the phase-lock-loop of one of said branches for suppressing signals which reach said one branch from the other branch via said first and second synthesizers.
Claim 7
Dependent Claim
150 words
A station for use in a telecommunication system having a plurality of stations which are arranged for radio communication with each other, said station including a transceiver comprising: a receiver branch with a first phase-lock-loop for providing a first local oscillator signal (LO1), and a transmitter branch with a second phase-lock-loop for providing a second local oscillator signal (LO2); the first and second phase-lock-loops respectively comprising first and second synthesizers which are coupled to each other; the receiver branch comprising a first frequency multiplier for multiplying the first local oscillator signal (LO1) by a first integer greater than one, the multiplied signal being produced at an output of the first multiplier which is coupled to an rf-path in the receiver branch; and a filter in the phase-lock-loop of one of said branches for suppressing signals which reach said one branch from the other branch via said first and second synthesizers.
Claim 8
Dependent Claim
128 words
A transceiver comprising: a receiver branch with a first phase-lock-loop for providing a first local oscillator signal (LO1), and a transmitter branch with a second phase-lock-loop for providing a second local oscillator signal (LO2); the first and second phase-lock-loops respectively comprising first and second synthesizers which are electrically coupled to each other; the receiver branch comprising a first frequency multiplier for multiplying the first local oscillator signal (LO1) by a first integer greater than one, the multiplied signal being produced at an output of the first frequency multiplier which is coupled to an rf-path in the receiver branch; and a first filter in the phase-lock-loop of one of said branches for suppressing signals which reach said one branch from the other branch via said first and second synthesizers.
Claim 9
Dependent Claim
128 words
A transceiver comprising: a receiver branch with a first phase-lock-loop for providing a first local oscillator signal (LO1), and a transmitter branch with a second phase-lock-loop for providing a second local oscillator signal (LO2); the first and second phase-lock-loops respectively comprising first and second synthesizers which are electrically coupled to each other; the receiver branch comprising a first frequency multiplier for multiplying the first local oscillator signal (LO1) by a first integer greater than one, the multiplied signal being produced at an output of the first frequency multiplier which is coupled to an rf-path in the receiver branch; and a first filter in the phase-lock-loop of one of said branches for suppressing signals which reach said one branch from the other branch via said first and second synthesizers.
Claim 10
Dependent Claim
143 words
A transceiver as claimed in claim 6, wherein the first filter is in the phase-lock-loop of the receiver branch, and the transmitter branch further comprises: a second frequency multiplier for multiplying the second local oscillator signal (LO2) by a second integer value greater than one, the multiplied signal being produced at an output of the second frequency multiplier which is coupled to an rf-path in the transmitter branch; and a second filter in the phase-lock-loop of the transmitter branch, said second filter (i) being a high pass filter which is coupled between the output of the second frequency multiplier and the second synthesizer, when said first filter is a low pass filter, and (ii) being a low pass filter which is coupled between an input of the second frequency multiplier and the second synthesizer, when said first filter is a high pass filter.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-11-12 | 2000-05-13 | 2000-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-11-12 | 2004-05-13 | 2004-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-11-12 | 2008-05-13 | 2008-11-12 | $7700.00 | Window Closed / Lapsed |