Ultrawideband Shared-Aperture Crossed Tapered Slot Antenna for 5G Applications

Abstract

A shared aperture scheme based on a tapered slot configuration is proposed in this letter. The main structure of the proposed antenna is an ultrawideband (UWB) crossed tapered slot with ground. In order to improve the practicality, four 1 × 4 dipole arrays containing feeding networks in the millimeter-wave (mm-wave) band are embedded in the four arms of the crossed tapered slot antenna. Four metal reflectors (or flares) are introduced to increase the gain of the dipole array. Owing to the ultrawideband characteristics of the tapered slot antenna, the proposed slot antenna can cover most sub-6 GHz communication frequency bands (such as LTE bands, N77–N79 bands, etc.). The proposed antenna has a compact volume of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$0.5 \lambda \times 0.5 \lambda \times 0.38 \lambda$</tex-math></inline-formula> , where λ is the free-space wavelength at 1.5 GHz. A prototype is designed, fabricated and tested. The measured results show that a −10 dB impedance bandwidth of 107% (1.5–5 GHz) and 15.8% (25–29.3 GHz) is realized in the sub-6 GHz band and mm-wave band, respectively. The isolation between all ports is higher than 30 dB. The gain variation of the antenna in the low-frequency range is 3.8–7.8 dBi. The peak gain of a single dipole array is approximately 14 dBi. The proposed antenna has the characteristics of shared aperture, low cost, and UWB, which is suitable for 5G microbase station applications.