Design and Analysis of a Dual-Polarized Wideband Inverted Dipole Bowtie Base Station Antenna for 5G Applications
Saranya Matta and
Sambhudutta Nanda
The manuscript presents the design and validation of an inverted bowtie dual-polarized antenna for 5G base station applications. The paper initiates with a comprehensive examination of antenna design, divided into two distinct phases: the evolving stage and the final stage. In the evolving stage, the antenna consists of two pairs of planar inverted bowtie dipoles, which are oriented perpendicularly to one another along their central axes. A balanced feed configuration has been effectively devised to facilitate optimal feeding to the bowtie antennas. The antenna, which is in an evolving stage of development, is engineered to operate at frequencies of 2.8 GHz on port 1 and 3.2 GHz on port 2. It features dual-polarization characteristics. The system ensures an isolation level exceeding 24 dB throughout the entire operational frequency range between the two ports. Additionally, it demonstrates an exceptional radiation efficiency of over 97% at the resonant frequencies. The maximum gain of this evolving stage antenna is 2.3 dBi. A 100 mm × 100 mm square ground plane has been integrated into the suggested antenna design in the final stage of design. Implemented on an FR4 substrate, the suggested antenna has a broad impedance bandwidth appropriate for 5G base-station services. This design has significantly improved gain, isolation, and radiation efficiency, as well as a broad-band resonant frequency range. The antenna proposed in the final stage is designed to operate within a frequency range of 2.66 GHz to 4.4 GHz, demonstrating wide-band characteristics. The design has been meticulously manufactured and calibrated to operate at a central frequency of 3.5 GHz. A -10 dB reflection coefficient with a wide band of 49.5% (which spans from 2.66 GHz to 4.4 GHz) is obtained from the measurements. Antenna-C, the suggested antenna discussed in this article, has a wide bandwidth of 1720 MHz for port 1, which spans the frequency range from 2.66 GHz to 4.4 GHz, and a wide bandwidth of 1710 MHz for port 2, which spans the frequency range from 2.91 GHz to 4.62 GHz. The isolation observed between the two ports has reached a maximum of -39.7 dB. Additionally, this optimization ensures a consistent level above -35 dB is maintained across the entire bandwidth. The results obtained from the proposed antenna, which incorporates a reflector, indicate that cross-polarization remains below -25 dB throughout the operating bandwidth. Furthermore, the front-to-back ratio is found to exceed 22 dB. The antenna design achieves a maximum gain of 7.5 dBi while consistently maintaining a gain greater than 6.3 dBi across the wide frequency range. The antenna dimensions at the lowest functional frequency of 2.66 GHz are 0.372λ0 × 0.355λ0, facilitating its extension into an array component.
