US3796948A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Standing wave detector
Assignee: Westinghouse Electric Corp
•
Filing: 1972-07-25
•
Granted: 1974-03-12
•
Expires: 1992-07-25
Abstract
Abstract A system and a method for determining the impedance of a given microwave device by measuring the standing wave in a transmission line is disclosed. A section of transmission line having a plurality of field-sensing probes therein is disposed between an RF signal source and the device. The output signals of these probes are sampled by the system, and the device impedance in terms of the reflection coefficient and the standing wave ratio are calculated using a mathematical process and a digital computer. The frequency of the RF source is variable permitting the measurements to be made over a predetermined frequency range.
Inventors
- 👤 F Wentworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:52
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/28; G01R27/32
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
143 words
A method for determining the standing wave ratio on a transmission line, comprising the steps of: a. connecting a section of transmission line, having a plurality of voltage sampling probes therein, between a signal source and a matched load; b. sampling the voltage output signals of each of said probes to obtain a first set of signals indicative of the voltage distribution along said transmission line; c. terminating said section of transmission line with a test load and sampling the output voltage of each of said probes to obtain a second set of voltage signals indicative of the voltage distribution along said transmission line; d. normalizing said second set of signals by dividing each of said signals by the corresponding signal in said first set, and e. calculating the standing wave ratio by solving the standing wave ratio equation using said normalized values.
Claim 2
Independent Claim
143 words
A method for determining the standing wave ratio on a transmission line, comprising the steps of: a. connecting a section of transmission line, having a plurality of voltage sampling probes therein, between a signal source and a matched load; b. sampling the voltage output signals of each of said probes to obtain a first set of signals indicative of the voltage distribution along said transmission line; c. terminating said section of transmission line with a test load and sampling the output voltage of each of said probes to obtain a second set of voltage signals indicative of the voltage distribution along said transmission line; d. normalizing said second set of signals by dividing each of said signals by the corresponding signal in said first set, and e. calculating the standing wave ratio by solving the standing wave ratio equation using said normalized values.
Claim 3
Independent Claim
182 words
A method for determining the standing wave ratio on a transmission line, comprising the steps of: a. positioning a plurality of field sampling probes in a transmission line with each of said probes being located a known distance from a reference plane; b. terminating said transmission line with a resistive load equal to the characteristic impedance of said transmission line; c. measuring the output of each of said probes to obtain a first set of values indicative of the field distribution along said transmission line; d. terminating said transmission line with the unit under test; and e. measuring the output of each of said field detecting probes to obtain a second set of values indicative of the field distribution along said transmission line; and f. calculating said standing wave ratio using the following equation: P 1 + R2 + 2R Cos (2BL-A) wherein: P the normalized output of a field sampling probe R magnitude of the reflection coefficient A phase angle of the reflection coefficient B propagation constant of the transmission line L distance of the probe from the impedance reference plane.
Claim 4
Independent Claim
182 words
A method for determining the standing wave ratio on a transmission line, comprising the steps of: a. positioning a plurality of field sampling probes in a transmission line with each of said probes being located a known distance from a reference plane; b. terminating said transmission line with a resistive load equal to the characteristic impedance of said transmission line; c. measuring the output of each of said probes to obtain a first set of values indicative of the field distribution along said transmission line; d. terminating said transmission line with the unit under test; and e. measuring the output of each of said field detecting probes to obtain a second set of values indicative of the field distribution along said transmission line; and f. calculating said standing wave ratio using the following equation: P 1 + R2 + 2R Cos (2BL-A) wherein: P the normalized output of a field sampling probe R magnitude of the reflection coefficient A phase angle of the reflection coefficient B propagation constant of the transmission line L distance of the probe from the impedance reference plane.
Claim 5
Dependent Claim
57 words
The method of determining the standing wave ratio of a transmission line in accordance with claim 1 wherein the first estimate of R is made by selecting the maximum value of P from a plurality of values for P obtained by sampling the output signals of said field sampling probes and assuming that Cos (2BL- A) 1.
Claim 6
Dependent Claim
84 words
The method of determining the standing wave ratio of a transmission line in accordance with claim 3 wherein the average value of A is determined by substituting the value of R determined in accordance with the procedure of claim 4 into the equation: P 1 + R2 + 2RCos (2BL-A) and using values of P obtained by sampling the output signals of said plurality of selectively positioned probes and averaging all the values of A so determined to obtain an average value of A.
Claim 7
Dependent Claim
48 words
The method of determining the standing wave ratio of a transmission line in accordance with claim 4 wherein the value of R is refined by substituting the value of A determined by the procedure of claim 5 into the equation P 1 + R2 + 2RCos (2BL- A).
Claim 8
Dependent Claim
61 words
The method of determining the standing wave ratio of a transmission line in accordance with claim 5 wherein an average value for R is determined by calculating R for each value of P obtained by sampliNg the output signals of each of said plurality of probes and averaging the values of R so obtained to determine an average value for R.
Claim 9
Dependent Claim
32 words
The method of determining the standing wave ratio of a transmission line where the calculation defined by claim 2 is an iterative process and is repeated until the required accuracy is obtained.
Claim 10
Dependent Claim
30 words
The method of determining the standing wave ratio of a transmission line in accordance with claim 2 wherein each of said procedures is controlled by a properly programmed digital computer.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-11 | 1977-09-10 | 1978-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-11 | 1981-09-10 | 1982-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-11 | 1985-09-10 | 1986-03-12 | $7700.00 | Window Closed / Lapsed |