US4479087A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Standing wave ratio and power meter
Assignee: Individual
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Filing: 1982-04-22
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Granted: 1984-10-23
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Expires: 2002-04-22
Abstract
Abstract An apparatus for measuring the Standing Wave Ratio and the RF transmitted power is in a transmission line. The ratio of the reflected component over the incident component of the transmitted signal is indicated on a logarithmic dot bar readout driven by the outputs of a stack of comparators. The comparators are separately referenced to a voltage divider ladder to which is applied a first DC voltage proportional to the incident component. The inputs of the comparator receive a second DC voltage signal proportional to the reflected component. The readout is provided with a scale directly indicating the Standard Wave Ratio. A similar circuit with linear readout referenced to a full scale voltage received the first DC voltage signal on its joint comparator inputs in order to display the power transmitted on the line.
Inventors
- 👤 John E. Althouse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:33
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/02; G01R27/04; G01R27/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
161 words
An apparatus for measuring the standing wave ratio of a signal on a transmission line between a radio frequency signal source and its load which comprises: means for generating a first DC voltage signal proportional to the amplitude of the incident component of the transmitted power; means for generating a second DC voltage signal proportional to the amplitude of the reflected component of the transmitted power; means for indicating in discreet increments the relative amplitude of the second DC voltage signal in relation to the amplitude of the first DC voltage signal; said means for indicating comprising: a stack of voltage comparators, each of said comparators having an input receiving the second DC voltage signal; a voltage divider chain to which is applied the first DC voltage signal; said voltage divider chain providing a series of scaled reference points individually connected to the reference inputs of said comparators; and means for displaying the output status of each of said voltage comparators.
Claim 2
Independent Claim
161 words
An apparatus for measuring the standing wave ratio of a signal on a transmission line between a radio frequency signal source and its load which comprises: means for generating a first DC voltage signal proportional to the amplitude of the incident component of the transmitted power; means for generating a second DC voltage signal proportional to the amplitude of the reflected component of the transmitted power; means for indicating in discreet increments the relative amplitude of the second DC voltage signal in relation to the amplitude of the first DC voltage signal; said means for indicating comprising: a stack of voltage comparators, each of said comparators having an input receiving the second DC voltage signal; a voltage divider chain to which is applied the first DC voltage signal; said voltage divider chain providing a series of scaled reference points individually connected to the reference inputs of said comparators; and means for displaying the output status of each of said voltage comparators.
Claim 3
Dependent Claim
40 words
The apparatus claimed in claim 1 which further comprises means for preventing the amplitude of the first DC voltage signal applied to the voltage divider chain from falling below the level of minimum amplitude of the second DC voltage signal.
Claim 4
Dependent Claim
18 words
The apparatus claimed in claim 2 wherein said divider chain provides reference points scaled in a logarithmic progression.
Claim 5
Dependent Claim
25 words
The apparatus claimed in claim 3 which further comprises means for indicating, in discreetly scaled increments, the absolute amplitude of the first DC voltage signal.
Claim 6
Dependent Claim
93 words
The apparatus claimed in claim 4 wherein said means for indicating the absolute amplitude comprises: a second series of voltage comparators, each having an input receiving the first DC voltage signal; a second voltage divider chain to which is applied a voltage commensurate with the full scale excursion of the first DC voltage signal; said second voltage divider chain providing a series of scales reference points individually connected to the reference inputs of the second series of voltage comparators; and means for displaying the output status of the second series of voltage comparators.
Claim 7
Dependent Claim
80 words
The apparatus claimed in claim 2 wherein said means for generating comprises: a transformer having a primary winding connected in series with the transmission line and a secondary winding having a first-end terminal, a second-end terminal, and central-tap terminal; a first positive rectifying circuit connected to said first-end terminal; a second positive rectifying circuit connected to said second-end terminal; and an adjustable capacitive divider circuit fed by the transmission line and having a central node connected to said central-tap terminal.
Claim 8
Dependent Claim
39 words
The apparatus claimed in claim 6 wherein said means for generating comprises: a first adjustable amplifier receiving the output of the first positive rectifying circuit; and a second adjustable amplifier receiving the output of the second positive rectifying circuit.
Claim 9
Dependent Claim
67 words
The apparatus claimed in claim 2 wherein said means for preventing comprises: an operational amplifier having its positive input biased to a near-zero positive reference point; a feedback loop comprising a diode having its anode connected to the output and its cathode connected to the negative input terminal of the operational amplifier; and said negative input also receiving said first DC voltage signal through a resistive path.
Claim 10
Dependent Claim
19 words
The apparatus claimed in claim 5 which comprises at least one monolithic integrated module of bar graph array drivers.
Claim 11
Dependent Claim
19 words
The apparatus claimed in claim 9 wherein said module comprises a series of scaled thresholds associated with said drivers.
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) | 1987-10-23 | 1988-04-23 | 1988-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-23 | 1992-04-23 | 1992-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-23 | 1996-04-23 | 1996-10-23 | $7700.00 | Window Closed / Lapsed |