Cross polarization in microwave antennas: Case study of a circular waveguide
DOI:
https://doi.org/10.37135/unach.ns.001.02.03Keywords:
Circular polarization, cross polarization, metallic rings, numerical analysis, patch antennaAbstract
During the last decade, the subject of antenna polarization attracts great interest. The improve of the cross polarization generates a distribution of a highly symmetric field in the aperture of the antenna, however, it is difficult to make low cross polarization circular sources to operate over a wide bandwidth. In this paper, a study case is presented to improve the cross polarization of a circular aperture. As the circular waveguide has a poor cross polarization, three possible solutions have been considered to improve the cross polarization in previous works. The first solution is based on a metallic disk, which after an optimization process obtains an external diameter of 90.42mm. The second solution is based on a metallic ring around the circular waveguide, the optimized dimension of the external diameter ring is 90.42mm with a thickness of 1.63mm. The third solution is based on two rings around the circular waveguide, which optimized dimensions of the rings are an outer diameter of 122.48mm, and an inner diameter of 90.42mm. This knowledge is valuable to explain the improvement of matching level of a patch antenna with a ring around 5.8 GHz.
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References
- Aznar, Á., Robert, J., Casals, J., Roca, L., Boris, S., and Bataller, M. (2004). Antenas. Spain: Universidad Politécnica de Catalunya. Iniciativa Digital Politécnica.
- Balanis, C. A. (2012). Advanced engineering electromagnetics. New York: John Wiley & Sons.
- Chen, C., Li, C., Zhu, Z., and Wu, W. (2017). Wideband and low cross polarization planar annual ring slot antenna. IEEE Antennas and Wireless Propagation Letters, 16, 3009-3013.
- Cho, T. and Lee, H. (2010). Dual-band surface wave suppression using soft surface structure. Paper presented at Antennas and Propagation (EuCAP), 2010 Proceedings of the Fourth European Conference, Retrieved from https://ieeexplore.ieee.org/.
- Dassault Systemes. (2018). CST Microwave Studio. https://www.cst.com.
- Kuloglu, M. and Chen, C. (2013). Ultra-wideband electromagnetic-polarization filter applications to conventional horn antennas for substantial cross-polarization level reductions. IEEE Antennas and Propagation Magazine, 55(2), 280-288.
- Kumar, C., Pasha, M. I., and Guha, D. (2015). Microstrip patch with nonproximal symmetric defected ground structure (dgs) for improved cross-polarization properties over principal radiation planes. IEEE Antennas and Wireless Propagation Letters, 14, 1412-1414.
- Ludwig, A. (1973). The definition of cross polarization. IEEE Transactions on Antennas and Propagation, 21(1), 116-119.
- Méndez, D. V. N. (2015). Nuevos sistemas radiantes realizados con tecnologías impresas. PhD thesis, Editorial Universitat Politècnica de València.
- Méndez, D. V. N., Suárez, L. F. C., and Escudero, M. B. Circular polarization patch antenna with low axial ratio in a large beamwidth. In Antennas and Propagation (EuCAP), 2013 7th European Conference, pp. 3330-3333. IEEE.
- Pour, Z. A. and Shafai, L. (2012). A simplified feed model for investigating the cross polarization reduction in circular-and elliptical-rim offset reflector antennas. IEEE Transactions on Antennas and Propagation, 60(3), 1261-1268.
- Pozar, D. M. (2009). Microwave Engineering. New York: John Wiley & Sons.
- Santillan, D. (2017). Theses: Diseño de antenas directivas de banda ancha a frecuencias de microondas. Universitat Politècnica de València.
- Thornton, J. and Huang, K. C. (2013). Modern lens antennas for communications engineering, volume 39. USA: John Wiley & Sons.
