A Dual-Polarized Bandwidth Enhanced Filtering Dipole Antenna Design for 5G

• Published in: IEEE access Vol. 11; pp. 78754 - 78767
• Main Authors: Celik, Feza Turgay, Joof, Sulayman, Karacuha, Kamil
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: 5G mobile communication; Antenna design; Antenna feeds; Antenna measurements; Antennas; Bandwidth; Bandwidths; Broadband; Broadband antenna; Broadband antennas; Design; dipole; Dipole antennas; Dual polarization (waves); dual-polarized; Electric arcs; Filtering; filtering antenna; Filtration; Frequency measurement; Impedance; Microstrip antennas; Parasitic elements (antennas); Patch antennas; Radiation; radiation null; Radiators; Reflector antennas; Resonators; Surface impedance; transmission zero
• ISSN: 2169-3536; 2169-3536
• DOI: 10.1109/ACCESS.2023.3299445

The present study proposes a dual-polarized bandwidth-enhanced filtering specialized dipole antenna design for 5G by employing a wide printed dipole, filtering resonators, a reflector surface, and specially designed balun structures. Such a configuration is commonly deployed in conventional base stations. To increase the antenna impedance and radiation bandwidth, a specifically designed, wide-printed flared dipole antenna structure is used as the main radiator element. Transmission zeros are introduced at both pass band edges to create a filtering response by engaging parasitic elements. The parasitic element for the higher frequency edge of the filtering is placed close to the maximum amount of the induced current on the radiator at the operating frequency, whereas the parasitic element for the lower frequency edge of the filtering is located close to the perpendicularly polarized structure. The antenna aims to create radiation nulls at the impedance bandwidth limits; therefore, the parasitic arcs are used to create surface currents that cancel the broadside radiation at the limits of the impedance bandwidth. The study illustrates a complete analysis of the broadband printed patch antenna having a filtering effect by parametric investigations on the dimensions and resulting physical phenomenon in detail. To demonstrate the approach, a prototype of the antenna is fabricated and measured. According to the measurement results, the antenna performs 76% impedance bandwidth between 2.49 GHz and 5.59 GHz with <inline-formula> <tex-math notation="LaTeX">|S_{11}| </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">|S_{22}| < -10 </tex-math></inline-formula> dB by providing exceptional isolation values of <inline-formula> <tex-math notation="LaTeX">|S_{21}| < -20 </tex-math></inline-formula> dB in entire operating band. The fabricated antenna has a stable radiation beamwidth with less than <inline-formula> <tex-math notation="LaTeX">\pm 5^{0} </tex-math></inline-formula> variation and the measured gain in the operating frequency is almost constant and equal to 8.2 dBi.