volume | PIER Journals

Abstract

The article describes the problem of spatial separation of devices operating in the same frequency range. The possibility of focusing electromagnetic fields in several specified regions of space is considered. The proposed method for focusing the electromagnetic field can be an additional method for separation devices that operate in the same frequency range. The system under consideration, consisting of space, radiating antennas and focusing points, is represented as an abstract multipole with the number of inputs equal to the number of radiating antennas and with a set of outputs equal to the number of focusing points. A coordinate system has been introduced that makes it possible to calculate the distances between radiation and focusing points. A method for calculating complex transmission coefficients between emission points and reception points is described. An analytical expression is obtained, a system of linear algebraic equations, which makes it possible to calculate the necessary amplitudes and phases of signals supplied to radiating antennas. A model in a computer-aided design system containing 56 radiating antennas is presented. 9 focus points were set, and 4 of them should have maxima of the electromagnetic field. The simulation confirmed the theoretical calculations. A method for optimizing the calculations of the initial amplitudes and phases by eliminating the elements of the characteristic matrix is considered. This made it possible to reduce the number of elements in the characteristic matrix.

1. Huo, Y., X. Dong, W. Xu, and M. Yuen, "Cellular and WiFi co-design for 5G user equipment," 2018 IEEE 5G World Forum (5GWF), 256-261, 2018, doi: 10.1109/5GWF.2018.8517059.
doi:10.1109/5GWF.2018.8517059

2. Sawada, H., S. Araki, R. Mukai, and S. Makino, "Grouping separated frequency components by estimating propagation model parameters in frequency-domain blind source separation," IEEE Transactions on Audio, Speech, and Language Processing, Vol. 15, No. 5, 1592-1604, July 2007, doi: 10.1109/TASL.2007.899218.
doi:10.1109/TASL.2007.899218

3. Álvarez, J. and R. Ayestarán, "Near field multifocusing on antenna arrays via non-convex optimisation," IET Microwaves, Antennas & Propagation, 754-764, 2014.
doi:10.1049/iet-map.2013.0563

4. Buffi, A., A. Serra, P. Nepa, et al. "A focused planar microstrip array for 2.4 GHz RFID readers," IEEE Trans. Antennas Propag., Vol. 58, No. 5, 1536-1544, 2010.
doi:10.1109/TAP.2010.2044331

5. Karimkashi, S. and A. A. Kishk, "Focusing properties of Fresnel zone plate lens antennas in the near-field region," IEEE Trans. Antennas Propag., Vol. 59, No. 5, 1481-1487, 2001.
doi:10.1109/TAP.2011.2123069

6. Bogosanovic, M. and A. G. Williamson, "Microstrip antenna array with a beam focused in the near-field zone for application in noncontact microwave industrial inspection," IEEE Trans. Instrum. Meas., Vol. 56, No. 6, 2186-2195, 2007.
doi:10.1109/TIM.2007.907954

7. Ismail, T. H., D. I. Abu-Al-Nadi, and M. J. Mismar, "Phase-only control for antenna pattern synthesis of linear arrays using the Levenberg-Marquardt algorithm," Electromagnetics, Vol. 24, No. 7, 555-564, 2004.
doi:10.1080/02726340490496707

8. Sun, L., P.-F. Li, S.-W. Qu, and S. Yang, "A near-field focused array antenna with reconfigurable elements," 2016 IEEE 5th Asia-Pacific Conference on Antennas and Propagation (APCAP), 319-320, 2016, doi: 10.1109/APCAP.2016.7843222.
doi:10.1109/APCAP.2016.7843222

9. Li, Y., S. Yu, N. Kou, Z. Ding, and Z. Zhang, "Cylindrical conformal array antenna for near field focusing," International Journal of RF and Microwave Computer-Aided Engineering, Vol. 32, No. 6, e23135, 2022.
doi:10.1002/mmce.23135

10. Smirnov, V. Yu., "Linear phased antenna arrays focused in the near field [Lineynie fazirovannie antennie reshetki, sfokusirovannie v blizhney zone]," News RGRTU [Vestnik RGRTU], 2008 (in Russian).

11. Obuhovec, V. A., "Synthesis of symmetrical microwave multipoles [Sintez simmetrichnih SVCH- mnogopolusnikov]," News of SFU [Izvestia YUFU], 177-185, 2018 (in Russian).

12. Cameron, R. J., "Analysis of multiport microwave networks," Microwave Filters for Communication Systems: Fundamentals, Design, and Applications, 2nd Edition, Chapter 5, 147-175, 2018.

13. James, J. R., P. S. Hall, and C. Wood, Microstrip Antenna Theory and Design, Peter Peregrinus Ltd., London, 1981.
doi:10.1049/PBEW012E

14. Golio, M. and J. Golio, RF and Microwave Circuits, Measurements, and Modeling, CRC Press, 2007.
doi:10.1201/9781420006704

15. Steer, M., Fundamentals of Microwave and RF Design, University of North Carolina Press, 2019.
doi:10.5149/9781469656892_Steer

16. Aaen, P. H., Modeling and Characterization of RF and Microwave Power FETs, Cambridge University Press, 2011.

17. Elfergani, I. T. E., A. S. Hussaini, R. A. Abd-Alhameed, C. H. See, M. B. Child, and J. Rodriguez, "Design of a compact tuned antenna system for mobile MIMO applications," 2012 Loughborough Antennas & Propagation Conference (LAPC), 1-4, 2012, doi: 10.1109/LAPC.2012.6403013.

18. Zhang, C., Q. Lai, and C. Gao, "Measurement of active S-parameters on array antenna using directional couplers," 2017 IEEE Asia Pacific Microwave Conference (APMC), 1167-1170, 2017, doi: 10.1109/APMC.2017.8251665.
doi:10.1109/APMC.2017.8251665

19. Mauch, S., Introduction to Methods of Applied Mathematics or Advanced Mathematical Methods for Scientists and Engineers, Mauch Publishing Company, 2003.

Dr. Denis Iuzvik

Professor Maksim Stepanov