US3584295A
Expired / Lapsed
US
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Selective measuring system for level and/or phase differences with digital calibration
Assignee: Wandel and Golterman GmbH and Co
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Filing: 1968-06-17
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Granted: 1971-06-08
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Expires: 1988-06-17
Abstract
Abstract To measure the attenuation and/or the phase angle of an impedance pad, an alternating current is passed alternately through the test pad and over a path independent of this pad into a heterodyning stage to generate, during a testing cycle, a beatfrequency oscillation of an amplitude and phase varying with the propagation characteristics of the test pad. The beat-frequency oscillation is then transmitted through a calibrated variableimpedance network constituting a digital attenuator or phase shifter which is progressively adjustable until its output matches a given reference voltage or phase. This reference parameter may be established during a calibrating cycle when the input wave bypasses the test pad in a zero or other reference position of the variable-impedance network while a feedback loop from a comparison circuit adjusts the generator of the reference signal to a balancing position; in a modified system, a fixed reference parameter may be alternately compared with corresponding parameters of a test wave and a standard wave, with concurrent stepping of two counters and resetting of one counter measures the difference in the magnitudes of these corresponding parameters.
Inventors
- 👤 Herbert Bayer
- 👤 Peter Harzer
- 👤 Gunther Hoffmann
- 👤 Bernd Zabel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:10
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/28
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
227 words
A system for measuring electric waves, comprising: circuit means for establishing a transmission path for an electric wave having a transmission-dependent parameter to be measured; a network of variable transmission characteristics which affect said parameter of a wave propagated over said transmission path, said network being connected to said circuits means and composed of a plurality of calibrated sections selectively insertable in said transmission path; signal-generating means for establishing a reference parameter; comparison means simultaneously connected to the outputs of said signal-generating means and of said network for matching said reference parameter with said parameter of said wave to be measured; selector means connected to be operated by said comparison means in response to the output thereof and coupled to said network for successively inserting different combinations of said calibrated sections into said transmission path until said comparison means indicates a balance; a source of oscillations for applying a standard wave; periodically operative switchover means for alternately applying said standard wave and said wave to be measured to the output of said circuit means for transmission over said path in A succession of calibrating and measuring cycles with establishment of said balance within each cycle; and register means coupled to said selector means for translating any difference between the settings of said selector means in successive calibrating and measuring cycles into an indication of the desired parameter.
Claim 2
Independent Claim
227 words
A system for measuring electric waves, comprising: circuit means for establishing a transmission path for an electric wave having a transmission-dependent parameter to be measured; a network of variable transmission characteristics which affect said parameter of a wave propagated over said transmission path, said network being connected to said circuits means and composed of a plurality of calibrated sections selectively insertable in said transmission path; signal-generating means for establishing a reference parameter; comparison means simultaneously connected to the outputs of said signal-generating means and of said network for matching said reference parameter with said parameter of said wave to be measured; selector means connected to be operated by said comparison means in response to the output thereof and coupled to said network for successively inserting different combinations of said calibrated sections into said transmission path until said comparison means indicates a balance; a source of oscillations for applying a standard wave; periodically operative switchover means for alternately applying said standard wave and said wave to be measured to the output of said circuit means for transmission over said path in A succession of calibrating and measuring cycles with establishment of said balance within each cycle; and register means coupled to said selector means for translating any difference between the settings of said selector means in successive calibrating and measuring cycles into an indication of the desired parameter.
Claim 3
Dependent Claim
41 words
A system as defined in claim 1 wherein the numerical weights of said calibrated sections in terms of their effect upon said desired parameter are the antilogarithms of respective powers of 2, said sections being serially disposed for insertion in cascade.
Claim 4
Dependent Claim
24 words
A system as defined in claim 2 wherein said network is subdivided into a plurality of decadic stages each composed of four calibrated sections.
Claim 5
Dependent Claim
21 words
A system as defined in claim 1 wherein said desired parameter is amplitude, said sections being calibrated in terms of attenuation.
Claim 6
Dependent Claim
12 words
A system as defined in claim 4 wherein said sections are transformers.
Claim 7
Dependent Claim
24 words
A system as defined in claim 1 wherein said desired parameter is phase angle and said sections are calibrated in terms of phase shift.
Claim 8
Independent Claim
266 words
A system for measuring electric waves, comprising: means for generating a local oscillation; circuit means for establishing a transmission path for an electric wave having at least one transmission-dependent parameter to be measured, said circuit means including a heterodyning stage for deriving a wave of fixed beat frequency from said local oscillation and said electric wave; a network of variable transmission characteristics which affect said parameter in said wave of fixed beat frequency, said network being connected to said circuit means and composed of a plurality of calibrated sections selectively insertable in said transmission path at a location beyond said heterodyning stage; signal-generating means for establishing a reference parameter; comparison means simultaneously connected to the outputs of said signal-generating means and of said network for matching said reference parameter with said parameter in said wave of fixed beat frequency; selector means connected to be operated by said comparison means in response to the output thereof and coupled to said network for successively inserting different combinations of said calibrated sections into said transmission path until said comparison means indicates a balance; a source of oscillations for applying a standard wave; periodically operative switchover means for alternately applying said standard wave and said wave of fixed beat frequency to the input of said circuit means for transmission over said path in a succession of calibrating and measuring cycles with establishment of said balance within each cycle; and register means coupled to said selector means for translating any difference between the settings of said selector means in successive calibrating and measuring cycles into an indication of the desired parameter.
Claim 9
Independent Claim
266 words
A system for measuring electric waves, comprising: means for generating a local oscillation; circuit means for establishing a transmission path for an electric wave having at least one transmission-dependent parameter to be measured, said circuit means including a heterodyning stage for deriving a wave of fixed beat frequency from said local oscillation and said electric wave; a network of variable transmission characteristics which affect said parameter in said wave of fixed beat frequency, said network being connected to said circuit means and composed of a plurality of calibrated sections selectively insertable in said transmission path at a location beyond said heterodyning stage; signal-generating means for establishing a reference parameter; comparison means simultaneously connected to the outputs of said signal-generating means and of said network for matching said reference parameter with said parameter in said wave of fixed beat frequency; selector means connected to be operated by said comparison means in response to the output thereof and coupled to said network for successively inserting different combinations of said calibrated sections into said transmission path until said comparison means indicates a balance; a source of oscillations for applying a standard wave; periodically operative switchover means for alternately applying said standard wave and said wave of fixed beat frequency to the input of said circuit means for transmission over said path in a succession of calibrating and measuring cycles with establishment of said balance within each cycle; and register means coupled to said selector means for translating any difference between the settings of said selector means in successive calibrating and measuring cycles into an indication of the desired parameter.
Claim 10
Dependent Claim
48 words
A system as defined in claim 7 wherein said selector means comprises reversible binary counter means and a source of stepping pulses for said counter means, said source being coupled to the output of said comparison means for emitting said stepping pulses in response to an imbalance signal.
Claim 11
Dependent Claim
45 words
A system as defined in claim 8 wherein said source is switchable provided with switch means for changing from a relatively high to a relatively low pulse rate in response to a decrease of the absolute magnitude of said imbalance signal below a predetermined threshold.
Claim 12
Dependent Claim
27 words
A system as defined in claim 9 wherein said source includes a pulse generator having input connections to said transmission path for energization by said beat frequency.
Claim 13
Dependent Claim
73 words
A system as defined in claim 8, further comprising timer means for periodically operating said switchover means to apply a wave to be measured and said standard wave to the input of said circuit means in a first cycle and in a second cycle, respectively, said counter means being provided with resetting means connected to said sWitchover means for establishing a starting position upon transition from one of said cycles to the other.
Claim 14
Dependent Claim
58 words
A system as defined in claim 11 wherein said counter means comprises a first counter and a second counter connected in parallel to said source for concurrent stepping thereby, said first counter being operative to insert said combinations of calibrated sections, said second counter being connected to operate said register means and being provided with said resetting means.
Claim 15
Dependent Claim
34 words
A system as defined in claim 7, further comprising adjustable level-control means connected in said transmission path ahead of said network for alternate traversal by said standard wave and the wave to be measured.
Claim 16
Dependent Claim
35 words
A system as defined in claim 13 wherein said level-control means includes a broadband amplifier and an amplitude gate responsive to the output of said amplifier for holding the output amplitude thereof within predetermined limits.
Claim 17
Dependent Claim
65 words
A system as defined in claim 7, for measuring attenuation and phase angle representing two transmission-dependent parameters, wherein said network comprises a first unit with sections calibrated in terms of attenuation and a second unit with sections calibrated in terms of phase shift, said units being connected in cascade to the output of said heterodyning stage for receiving said wave of fixed beat frequency therefrom.
Claim 18
Independent Claim
295 words
A system for measuring electric waves, comprising: circuit means for establishing a transmission path for an electric wave having at least one transmission-dependent parameter to be measured; a network of variable transmission characteristics which affect said parameter of a wave propagated over said transmission path said network being connected to said circuit means and composed of a plurality of calibrated sections selectively insertable in said transmission path; signal-generating means for establishing a reference parameter, including at least one variable voltage generator and control means therefor; comparison means connected to the outputs of said voltage generator and of said network for matching said reference parameter with said parameter of the wave to be measured, said comparison means being provided with a feedback loop extending from the output thereof to said control means; selector means connected to be operated by said comparison means in response to the output thereof and coupled to said network for successively inserting different combinations of said calibrated sections into said transmission path until said comparison means indicates a balance; a source of oscillations for supplying a standard wave; periodically operative switchover means for alternately applying said standard wave and the wave to be measured to the input of said circuit means in a succession of calibrating and measuring cycles and for closing said feedback loop during calibrating cycles only, thereby adjusting said voltage generator to establish a reference input for said comparison means matching the output of said network applied to said comparison means at the end of an immediately preceding measuring cycle; reactive clamping means in said feedback loop for holding said reference input substantially constant during a subsequent measuring cycle; and register means coupled to said selector means for translating the setting thereof into an indication of the desired parameter.
Claim 19
Independent Claim
295 words
A system for measuring electric waves, comprising: circuit means for establishing a transmission path for an electric wave having at least one transmission-dependent parameter to be measured; a network of variable transmission characteristics which affect said parameter of a wave propagated over said transmission path said network being connected to said circuit means and composed of a plurality of calibrated sections selectively insertable in said transmission path; signal-generating means for establishing a reference parameter, including at least one variable voltage generator and control means therefor; comparison means connected to the outputs of said voltage generator and of said network for matching said reference parameter with said parameter of the wave to be measured, said comparison means being provided with a feedback loop extending from the output thereof to said control means; selector means connected to be operated by said comparison means in response to the output thereof and coupled to said network for successively inserting different combinations of said calibrated sections into said transmission path until said comparison means indicates a balance; a source of oscillations for supplying a standard wave; periodically operative switchover means for alternately applying said standard wave and the wave to be measured to the input of said circuit means in a succession of calibrating and measuring cycles and for closing said feedback loop during calibrating cycles only, thereby adjusting said voltage generator to establish a reference input for said comparison means matching the output of said network applied to said comparison means at the end of an immediately preceding measuring cycle; reactive clamping means in said feedback loop for holding said reference input substantially constant during a subsequent measuring cycle; and register means coupled to said selector means for translating the setting thereof into an indication of the desired parameter.
Claim 20
Dependent Claim
47 words
A system as defined in claim 16 wherein said circuit means includes means for generating a local oscillation and a heterodyning stage for deriving a fixed beat frequency from said local oscillation and a wave to be measured and for feeding said beat frequency to said network.
Claim 21
Dependent Claim
50 words
A system as defined in claim 16 wherein said desired parameter is phase shift and said voltage generator comprises a variable oscillator, said control means including electronically variable reactance means responsive to the output of said comparison means for locking and oscillator in step with the output of said nEtwork.
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) | 1974-06-07 | 1974-12-07 | 1975-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-07 | 1978-12-07 | 1979-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-07 | 1982-12-07 | 1983-06-08 | $7700.00 | Window Closed / Lapsed |