US6782246B1
Expired / Lapsed
US
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Method for producing a test signal
Assignee: Rohde and Schwarz GmbH and Co KG
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Filing: 2000-09-04
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Granted: 2004-08-24
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Expires: 2020-09-04
Abstract
Abstract An apparatus and method are described for producing a test signal with a desired signal-to-noise ratio on a selectable output frequency for measuring a transmission system. A carrier signal, generated from a carrier signal, and a noise signal are remixed with the carrier signal in a bandwidth equal to or smaller than a smallest signal bandwidth of the transmission system. The levels of the carrier signal and the noise signal are adjusted to a predetermined ratio based on a measurement of the remixed carrier signal and the remixed noise signal. The noise signal is attenuated and added to the carrier signal until the desired signal-to-noise ratio is attained.
Inventors
- 👤 Erhard Kretschmer
- 👤 Johann Mieslinger
- 👤 Gregor Kleine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:50
CPC Classifications
H; H04; H04N; H04N17/00; H04B; H04B17/00; H04B17/30; H04B17/309; H04B17/346
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
107 words
A method for producing a test signal with a desired signal-to-noise ratio on a selectable output frequency for measuring a transmission, said method comprising: remixing a carrier signal, generated from a carrier frequency, and a noise signal with the carrier frequency in a bandwidth equal to or smaller than a smallest signal bandwidth of the transmission system; regulating levels of the carrier signal and the noise signal to a predetermined ratio based on a measurement of the remixed carrier signal and the remixed noise signal; and attenuating the noise signal and adding the attenuated noise signal to the carrier signal until the desired signal-to-noise ratio is attained.
Claim 2
Independent Claim
107 words
A method for producing a test signal with a desired signal-to-noise ratio on a selectable output frequency for measuring a transmission, said method comprising: remixing a carrier signal, generated from a carrier frequency, and a noise signal with the carrier frequency in a bandwidth equal to or smaller than a smallest signal bandwidth of the transmission system; regulating levels of the carrier signal and the noise signal to a predetermined ratio based on a measurement of the remixed carrier signal and the remixed noise signal; and attenuating the noise signal and adding the attenuated noise signal to the carrier signal until the desired signal-to-noise ratio is attained.
Claim 3
Dependent Claim
14 words
A method according to claim 1 , wherein the predetermined ratio is one (1).
Claim 4
Dependent Claim
19 words
A method according to claim 1 , wherein said attenuating is performed by means of an adjustable calibration line.
Claim 5
Dependent Claim
42 words
A method according to claim 1 , further comprising modulating a local carrier signal to generate the carrier signal, wherein the carrier signal and the noise signal are remixed with the local carrier signal to an intermediate frequency in a basic band.
Claim 6
Dependent Claim
24 words
A method according to claim 1 , wherein said regulating the levels is performed with or without interruption of generation of the test signal.
Claim 7
Dependent Claim
29 words
A method according to claim 1 , wherein said regulating the levels is performed by regulating the level of the noise signal and/or the level of the carrier signal.
Claim 8
Dependent Claim
18 words
A method according to claim 1 , wherein said regulating the ratio of the levels is performed automatically.
Claim 9
Independent Claim
108 words
An apparatus for producing a test signal with a desired signal-to-noise ration on a selectable output frequency for measuring a transmission system, said apparatus comprising: a first adjustable calibration line for generating a noise signal based on a noise source; a level detector receiving the noise signal and a carrier signal via a toggle switch, wherein the first calibration line is controlled based on an output of the level detector so that a level of the noise signal is in a predetermined ratio with a level of the carrier signal; and a second adjustable calibration line for attenuating the noise signal and adjustable to the desired signal-to-noise ratio.
Claim 10
Independent Claim
108 words
An apparatus for producing a test signal with a desired signal-to-noise ration on a selectable output frequency for measuring a transmission system, said apparatus comprising: a first adjustable calibration line for generating a noise signal based on a noise source; a level detector receiving the noise signal and a carrier signal via a toggle switch, wherein the first calibration line is controlled based on an output of the level detector so that a level of the noise signal is in a predetermined ratio with a level of the carrier signal; and a second adjustable calibration line for attenuating the noise signal and adjustable to the desired signal-to-noise ratio.
Claim 11
Dependent Claim
56 words
An apparatus according to claim 8 , further comprising: the wanted signal (C) is generated by modulation of the carrier frequency of a local oscillator (LO) in a modulator (MO) and an inverse mixer (MI), supplied with the frequency of the local oscillator (LO), is arranged between the reversing switch (U) and the level detector (D).
Claim 12
Dependent Claim
39 words
An apparatus according to claim 8 , further comprising a fixed frequency band filter coupled before the level detector, said band filter having a bandwidth (B) equal to or smaller than a smallest signal bandwidth of the transmission system.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2007-08-24 | 2008-02-23 | 2008-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-08-24 | 2012-02-23 | 2012-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-08-24 | 2016-02-23 | 2016-08-24 | $7700.00 | Window Closed / Lapsed |