A Wideband Circularly Polarized Antenna Array Using Irregularly Shaped Hexagonal Slot Optimized by Iterative Taguchi’s Method

This study proposes a novel 2.45 GHz wideband <inline-formula> <tex-math notation="LaTeX">$2\times 2$ </tex-math></inline-formula> circularly polarized (CP) slot antenna array, which consists of irregularly hexagonal slot CP antenna elements and a sequentially rotat...

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Bibliographic Details
Main Authors: Wei-Chung Weng, Chi-Keong Wong
Format: Article
Language:English
Published: IEEE 2025-01-01
Series:IEEE Access
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Online Access:https://ieeexplore.ieee.org/document/10937751/
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Summary:This study proposes a novel 2.45 GHz wideband <inline-formula> <tex-math notation="LaTeX">$2\times 2$ </tex-math></inline-formula> circularly polarized (CP) slot antenna array, which consists of irregularly hexagonal slot CP antenna elements and a sequentially rotated phase feed network. The CP antenna element has a single-layer, single-fed, simple structure. Designing the CP antenna element does not require stacked layers, dual-feed networks, or additional resonant/perturbing components. The antenna element, including its hexagonal slot, is optimized using the iterative Taguchi&#x2019;s optimization method to broaden the antenna&#x2019;s impedance and axial ratio bandwidths. Detailed CP antenna design approaches, optimization settings, CP wave mechanisms, and the element&#x2019;s and antenna array&#x2019;s results, are discussed. Good agreements between measured and simulated results are revealed, confirming the validity of the proposed designs. The proposed wideband <inline-formula> <tex-math notation="LaTeX">$2\times 2$ </tex-math></inline-formula> CP irregularly shaped hexagonal slot antenna array provides a maximum boresight gain of 15.3 dBic and a CP bandwidth of 47.6% from 2.13 to 3.46 GHz. At the center frequency of 2.45 GHz, the cross-polarization level in the main beam direction is less than &#x2013;23.6 dB; the front-to-back ratio is larger than 40 dB; and the back-lobe level is less than &#x2013;22 dB. A comparison of the proposed array with other <inline-formula> <tex-math notation="LaTeX">$2\times 2$ </tex-math></inline-formula> wideband CP antenna arrays in the literature shows that it has a broader CP bandwidth and higher gain than those of all the compared antenna arrays. This study also demonstrates that irregular radiating geometries provide a novel approach to antenna design.
ISSN:2169-3536