Patent US3879733A successfully refreshed from Google Patents.
US3879733A
Expired / Lapsed
US
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Method and apparatus for determining near-field antenna patterns
Assignee: United States Department of the Navy
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Filing: 1973-10-01
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Granted: 1975-04-22
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Expires: 1993-10-01
Abstract
Abstract A cost-effective and practical technique for obtaining far-field patterns of complex radiating or receiving structures such as ships, aircraft, or shore site antennas. Actual phase and amplitude measurements are obtained in the near-field and then they are processed in a digital computer using theoretical Zmatrix numerical techniques to calculate the far-field patterns by solving the matrix for the current distribution on the structure. By using near-field measurements, the method is significantly less expensive than either modeling or complete computer solutions, yet the results achieved are highly accurate.
Inventors
- 👤 Peder M Hansen
- 👤 John W Rockway
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:38
CPC Classifications
G; G01; G01R; G01R29/00; G01R29/08; G01R29/10
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
120 words
A method for determining far-field radiation patterns of a complex structure and comprising the steps of exciting said structure with RF energy from a stable source; measuring phase and amplitude for three mutually-orthogonal polarizations at a plurality of known points in the near-field of said structure; converting the measured phase and amplitude, the coordinates of said points relative to said structure, and the pOlarization of said corresponding measurements into digital data; programming digital computer apparatus to calculate the impedance matrix of a rough model of said structure; feeding said digital data into said apparatus for inverting said impedance matrix and thereby providing the current distribution of said structure; converting said current distribution in said apparatus into said far-field radiation patterns.
Claim 2
Independent Claim
120 words
A method for determining far-field radiation patterns of a complex structure and comprising the steps of exciting said structure with RF energy from a stable source; measuring phase and amplitude for three mutually-orthogonal polarizations at a plurality of known points in the near-field of said structure; converting the measured phase and amplitude, the coordinates of said points relative to said structure, and the pOlarization of said corresponding measurements into digital data; programming digital computer apparatus to calculate the impedance matrix of a rough model of said structure; feeding said digital data into said apparatus for inverting said impedance matrix and thereby providing the current distribution of said structure; converting said current distribution in said apparatus into said far-field radiation patterns.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein said stable source comprises a transmitter.
Claim 4
Dependent Claim
26 words
The method of claim 2 wherein said phase and amplitude measurements are made by means of a movable probe connected at its output to a receiver.
Claim 5
Dependent Claim
15 words
The method of claim 1 wherein said impedance matrix is calculated using the Pocklington equation.
Claim 6
Independent Claim
54 words
A method for determining far-field patterns of a complex radiating structure comprising the steps of measuring phase and amplitude in the near-field of said structure, processing the resultant measurements in digital computer apparatus to determine the impedance matrix of said structure and to invert said matrix to determine the current distribution of said structure.
Claim 7
Independent Claim
54 words
A method for determining far-field patterns of a complex radiating structure comprising the steps of measuring phase and amplitude in the near-field of said structure, processing the resultant measurements in digital computer apparatus to determine the impedance matrix of said structure and to invert said matrix to determine the current distribution of said structure.
Claim 8
Independent Claim
54 words
A method for determining far-field patterns of a complex radiating structure comprising the steps of measuring phase and amplitude in the near-field of said structure, processing the resultant measurements in digital computer apparatus to determine the impedance matrix of said structure and to invert said matrix to determine the current distribution of said structure.
Claim 9
Independent Claim
54 words
A method for determining far-field patterns of a complex radiating structure comprising the steps of measuring phase and amplitude in the near-field of said structure, processing the resultant measurements in digital computer apparatus to determine the impedance matrix of said structure and to invert said matrix to determine the current distribution of said structure.
References Cited (Backward Citations)
US2548836A
Cited
US3166748A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |