EP0496381A2
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EP
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Method and apparatus for testing phase shifter modules of a phased array antenna
Assignee: Raytheon Co
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Filing: 1992-01-22
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Granted: —
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Expires: 2012-01-22
Abstract
Abstract Faulty subarray module circuit boards are detected in a phased array antenna (68) having many subarray module circuit boards while the antenna (68) is fully assembled and operationally integrated with a radar (70) system. A far field radio frequency test source (73) illuminates the antenna (68). Binary digital signals that control subarray steering bits are set to a reference setting. A particular subarray module circuit board that is under test has its 180° main phase bit toggled between 0° and 180°. The radar (70) selects the output of that particular subarray module by Doppler filter type of software filtering. The amplitude of the in-phase and quadrature phase (71, 72) signals from the radar (70) is recorded. The binary digital signals that control subarray steering bits are set to a second setting. The 180° main phase bit of the module under test is again toggled between 0° and 180°. The output of the module under test is again selected by Doppler filter type of software filtering. The amplitude of the in-phase and quadrature phase signals from the radar (70) is recorded. The phase difference from the reference setting to the second setting is computed and compared with a predetermined threshold. If desired, the test source (69) may have a multi-element feed including multiple dipoles, each dipole having a radiation pattern wide enough to cover two rows of subarray modules, the test source (69) being switched to the particular one of the dipoles that illuminates the row including the module under test.
Inventors
- 👤 Sien-Chang Charles Lui
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 13:24
CPC Classifications
G; G01; G01R; G01R29/00; G01R29/08; G01R29/10; G01S; G01S7/00; G01S7/02; G01S7/40; G01S7/4052; H; H01; H01Q; H01Q3/00; H01Q3/26; H01Q3/267; G01S7/4082; G01S7/4095
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
185 words
A method for testing a phased array radar antenna (68) having a plurality of subarray steering bit networks (22-24) that provide subarray steering bits in unison with response to binary digital signals but that cannot be individually controlled, characterized by the following steps: - illuminating the phased array radar antenna (68) with a radio frequency test signal; - setting the binary digital signals that control subarray steering bits to a reference setting; - toggling the 180° bit of the main phase bits of a subarray module (10) under test between 0° and 180°; - selecting the output of the subarray module (10) under test by employing a predetermined filter (74, 75); - setting the binary digital signals that control subarray steering bits to a second setting; - toggling the 180° bit of the main phase bits of the subarray module (10) under test between 0° and 180°; - selecting the output of the subarray module (10) under test by employing a predetermined filter (74, 75); and - calculating the phase difference from the reference setting to the second setting and comparing it with a threshold.
Claim 2
Dependent Claim
28 words
The method of claim 1, characterized by the step of recording the inphase and quadrature phase channel (71, 72) outputs from the radar receiver (70) for each setting.
Claim 3
Dependent Claim
39 words
The method of claim 1 or 2, characterized in that each step of selecting the output of the subarray module (10) comprises the step of selecting the output of the subarray module (10) under test by employing Doppler filtering.
Claim 4
Dependent Claim
41 words
The method of claim 1 or 2, characterized in that each step of selecting the output of the subarray module (10) comprises the step of selecting the output of the subarray module (10) under test by employing a predetermined software filtering.
Claim 5
Dependent Claim
44 words
The method of claim 1 or 2, characterized in that each step of selecting the output of the subarray module (10) comprises the step of selecting the output of the subarray module (10) under test by employing a Doppler filter type of software filtering.
Claim 6
Independent Claim
218 words
A method for testing a phased array radar antenna (68) having a plurality of subarray steering bit networks (22-24) that provide subarray steering bits in unison in response to binary digital signals but cannot be individually controlled, characterized by the following steps: - illuminating the phased array radar antenna (68) with a radio frequency test signal; - setting the binary digital signals that control subarray steering bits to a reference setting; - toggling the 180° bit of the main phase bits of a subarray module (10) under test between 0° and 180°; - selecting the output of the subarray module (10) under test by employing a Doppler filter type of software filtering; - recording the in-phase and quadrature phase channel outputs from the radar receiver (70); - setting the binary digital signals that control subarray steering bits to a second setting; - toggling the 180° bit of the main phase bits of the subarray module (10) under test between 0° and 180°; - selecting the output of the subarray module (10) under test by employing a Doppler filter type of software filtering; - recording the in-phase and quadrature phase channel (71, 72) outputs from the radar receiver (70); and - calculating the phase difference from the reference setting to the second setting and comparing it with a threshold.
Claim 7
Independent Claim
182 words
An apparatus for testing subarray modules (10) of a phased array antenna (68) while it is integrated in a radar system characterized by: - a phased array antenna (68) comprising a plurality of subarray modules (10) arrayed in a matrix pattern of rows and columns; - a radio frequency receiver (70) coupled to said antenna (68) for indicating the response of said subarray modules (10) when illuminated with radio frequency energy; - a test source (69) of radio frequency energy; and - a multi-element feed comprising multiple dipoles (81-85) coupled to said test source (69) of radio frequency energy, and wherein said multi-element feed is disposed adjacent said phased array and having said phased array antenna (68) aimed toward said multi-element feed, each dipole (81-85) of said multi-element feed having a radiation pattern wide enough to cover two rows of said plurality of subarry modules (10), and wherein the test source (69) is switchable to the particular one of said dipoles (81-85) that illuminates the particular row of a particular one of said plurality of subarray modules (10) that is under test.
Claim 8
Dependent Claim
30 words
The apparatus of claim 7, characterized in that said multi-element feed comprises a mast (86) and an RF cable (87) coupled to said test source (69) of radio frequency energy.
Claim 9
Dependent Claim
43 words
The apparatus of claim 7 or 8, characterized in that the phased array antenna (68) has a plurality of subarray steering bit networks (22-24) that provide subarray steering bits in unison in response to binary digital signals but that cannot be individually controlled.
Claim 10
Dependent Claim
161 words
The appratus of any of claims 7 - 9, characterized in that the phased array antenna (68) is testable by: - illuminating the phased array antenna (68) with a radio frequency test signal; - setting the binary digital signals that control subarry steering bits to a reference setting; - toggling the 180° bit of the main phase bits of a subarry module (10) under test between 0° and 180°; - selecting the output of the subarray module (10) under test by employing a predetermined filter (74, 75); - setting the binary digital signals that control subarray steering bits to a second setting; - toggling the 180° bit of the main phase bits of the subarray module (10) under test between 0° and 180°; - selecting the output of the subarray module (10) under test by employing a predetermined filter (74, 75); and - calculating the phase difference from the reference setting to the second setting and comparing it with a threshold.
Claim 11
Dependent Claim
35 words
The apparatus of claim 10, characterized in that the phased array antenna (68) is further testable by recording the in-phase and quadrature phase channel (71, 72) outputs from the radar receiver (70) for each setting.
Claim 12
Dependent Claim
33 words
The apparatus of claim 9 or 10, characterized in that the phased array antenna (68) is further testable by selecting the output of the subarray module (10) under test by employing Doppler filtering.
Claim 13
Dependent Claim
35 words
The apparatus of claim 9 or 10, characterized in that the phased array antenna (68) is further testable by selecting the output of the subarray module (10) under test by employing a predetermined software filtering.
Claim 14
Dependent Claim
38 words
The apparatus of claim 9 or 10, characterized in that the phased array antenna (68) is further testable by selecting the output of the subarray module (10) under test by employing a Doppler filter type of software filtering.
References Cited (Backward Citations)
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