A. I. Gigolo1, G. Yu. Kuznetsov2, V. S. Temchenko3
1, 3 Moscow Aviation Institute (National Research University) (Moscow, Russia)
2 Research Institute of Precision Instruments (Moscow, Russia)

In this paper, a new method for solution of the calibration problem has been presented. The goal is to determine the amplitudes and phases of radiating elements which comprise the conformal array under test (AUT). This method is based on the a priori information about complex amplitudes of radiating elements in the “reference” antenna array. This “reference” array has the same geometry and the same type of elements as the AUT.

The solution of calibration problem uses the results of the measured radiated fields, obtained both from the AUT and the “reference” array, with the geometry of measurements and measurement probe (MP) being the same in both cases. Accuracy of the solution is determined by field measurement uncertainties and uncertainties of the MP’s characteristics. Conventional approach to calibration assumes that the characteristics of MP are known and uses these data to compensate MP’s influence. Complexity of the solution depends on the measurement geometry and the algorithm of measured data processing. In this case, accuracy of the complex amplitudes of excitations depends on probe’s impedance matching and accuracy of measured data.

The proposed method for the solution of calibration problem is based on forming sum-difference voltages and their combined processing. This allows increasing the accuracy of AUT calibration by excluding the influence of MP. Combined processing of AUT and “reference” array data also simplifies the separation of the signal from the radiating element under test and the calibrated element.

A numerical simulation has been used to model the calibration process. Linear equidistant array with N = 100 elements was used as AUT, measured field was calculated with probe characteristics taken into account. Complex amplitudes of excitations have been found using the proposed method and compared to other known methods. The accuracy of different methods in presence of measurement probe uncertainties has been evaluated.

Gigolo A.I., Kuznetsov G.Yu., Temchenko V.S. New method of phased antenna array calibration using near-field measurements. Antennas. 2022. № 4. P. 33–45. DOI: https://doi.org/10.18127/j03209601-202204-04 (in Russian)

1. Bucci O.M., Migliore M.D., Panariello G. Accurate diagnosis of conformal arrays from near-field data using the matrix method. IEEE Transactions on Antennas and Propagation. 2005. V. 53. № 3. P. 1114–1120.
2. Newell A.C. Error analysis techniques for planar near-field measurements. IEEE Transactions on Antennas and Propagation. 1988. V. 36. № 6. P. 754–768.
3. Sarkar T.K., Taaghol A. Near-field to near/far-field transformation for arbitrary near-field geometry utilizing an equivalent electric current and MoM. IEEE Transactions on Antennas and Propagation. 1999. V. 47. № 3. P. 566–573.
4. Long R., Ouyang J., Yang F., Li Y., Zhang K. Calibration method of phased array based on near-field measurement system. Progress In Electromagnetics Research C. 2017. V. 71. P. 25–31.
5. Takahashi T., Konishi Y., Makino S., Ohmine H., Nakaguro H. Fast measurement technique for phased array calibration. IEEE Transactions on Antennas and Propagation. 2008. V. 56. № 7. P. 1888–1899.
6. Migliore M.D. A compressed sensing approach for array diagnosis from a small set of near-field measurements. IEEE Transactions on Antennas and Propagation. 2011. V. 59. № 6. P. 2127–2133.
7. Wei L., Weibo D., Qiang Y., Ying S. A hybrid diagnosis method for defective array elements based on compressive sensing and iterative shrinkage thresholding algorithm. 2017 International Symposium on Antennas and Propagation (ISAP). Phuket, Thailand. 2017. P. 1–2.
8. Kuznetsov G., Temchenko V., Miloserdov M., Voskresenskiy D. Modifications of active phased antenna arrays near-field diagnosis method based on compressive sensing. International Journal of Microwave and Wireless Technologies. 2019. V. 11. P. 568–576.
9. Massa A., Rocca P., Olivieri G. Compressive sensing in electromagnetics – A review. IEEE Antennas and Propagation Magazine. 2015. V. 57. № 1. P. 224–238.
10. Calvetti D., Morigi S., Reichel L., Sgallari F. Tikhonov regularization and the L-curve for large discrete ill-posed problems. Journal of Computational and Applied Mathematics. 2000. № 123. P. 423–446.
11. Schmidt C., Leibfritz M., Eibert T. Fully probe-corrected near-field far-field transformation employing plane wave expansion and diagonal translation operators. IEEE Transactions on Antennas and Propagation. 2008. V. 56. № 3. P. 737–746.
12. Yinusa K.A., Eibert T.F. Multi-probe measurement technique for echo suppression in near-field measurements. 7th European Conference on Antennas and Propagation (EuCAP). 2013. P. 3889–3893.
13. Kuznetsov G.Yu., Temchenko V.S. Rekonstruktivnaya diagnostika fazirovannykh antennykh reshetok s ispol'zovaniem metoda «opoznanie so szhatiem». Antenny. 2017. № 1. S. 14–21. (in Russian)