Multi-Resonance Miniaturized Base Station Antenna Using Dual Resonance Rings and Fractal Technology

This paper presents a novel broadband dual-polarized dipole antenna with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\pm 45^{\circ}$</tex> polarization. The antenna employs a bent structure and fractal technology in both horizontal and vertical directions to extend the low-frequency current path, thereby broadening the bandwidth. The inclusion of dual resonance rings facilitates multi-frequency resonance, enhancing the antenna's impedance matching and subsequently increasing the bandwidth. The proposed miniaturized antenna has dimensions of only <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.29\lambda\times 0.29\lambda$</tex>, Simulation results demonstrate that the antenna achieves a bandwidth of 1.7-2.83 GHz (S11 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$&lt; -15\text{dB})$</tex>, with polarization isolation greater than 30 dB, a gain of 8 dB, and a stable 3 dB beam width of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$70^{\circ}\pm 1^{\circ}$</tex>. Additionally, the 10 dB beam width is <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$127^{\circ}\pm 2^{\circ}$</tex>, ensuring a stable radiation pattern within the operating frequency band. This antenna shows promise as a viable option for future base station communication systems.