V. Vechtomov Ph.D. (Eng.), Associate Professor at «Radio-electronic systems and devices» chair, Bauman Moscow State Technical University
A.A. Genus, A.A. Rogozin
The article describes automate test-bench with «мини-БЭК» for calibrating and checking of subarray parameters for digital array with few number of channels. During high-power operation of test-bench «СанПиН 18.104.22.1681-03» microwave radiation personal protection requirements are provided.
The rotating-element electric field vector method is used as test-bench operation algorithm. Rev-method is easily realized, used in operation closed to normal operation of digital array, it considers digital array channels mutual influence, has high performance, provides same test conditions during channels switching, inequality of test conditions is absent that are regular for contact methods. For subarrays signal initial phase identification reference channel built in test-bench is introduced.
Test-bench basic elements: test and reference subarrays of digital array; «миниБЭК»; power meter, printer, microwave generator, faucets, circulator and personal computer. Test-bench uses: microwave generator Rohde & Schwarz SMB100A and power meter Rohde & Schwarz NRP-Z24.
«МиниБЭК» is destined to provide servicers safety operation conditions and create conditions for plane wave in «миниБЭК» work zone. It made is airproof metal box 724x724x1351 mm2, it’s top end wall has a collar to install test subarray of digital array and OK. «миниБЭК» has radar-absorbent liner walls, kind of «Don-17». «МиниБЭК» is mounted with collimator lens, that allows twofold degradation of «МиниБЭК» longitudinal dimension and more than twofold weight degradation.
Testing process is automated for minimal staff operation during testing. Testing process and test-bench are designed so, that switching to transmitting mode from receiving mode doesn’t need mechanical device switching, transfer from tests to measurements is automated. Practically, calibration time is defined only by time of digital array’s sabarray installation to «миниБЭК» and time of subarray’s starting operation.
Total test-bench operation error that consists of: instruments accuracy; number of calibrating digital array channels; inequality of gain-phase characteristics in test zone; setting accuracy of digital array to receive collar of «миниБЭК» is described. Accuracy assessment of automated test-bench operation allows to talk about high measurement accuracy (mean square phase error is 1.6o and mean square gain error is 0.12 dB during concurrent operation of eight channels).
Test-bench is designed for integration to automated manufacturing lines of digital array in mass production conditions and usage in QC department and it makes materially reducing materially of time and labour intensity of digital array’s calibrating process during production possible. Working design documentation «РКЕМ.411151.001» for described calibrating and parameter checking few elements subarrays test-bench is developed.
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