Dual-Band Dual-Polarized Antenna and Array With Enhanced Bandwidth for 5G Millimeter-Wave Applications

This letter presents a low-profile, dual-band dual-polarized (DBDP) millimeter-wave antenna and array, covering the fifth-generation (5G) of the n257–n258 band and n260–n261 band, simultaneously. The DBDP element is composed of four modified rectangular patches on the top, four shorted L-shaped strips under the patches, and a crossed microstrip that serves as the feed. The rectangular patches serve as the radiators of both bands with the shorter sides for the high-band operation and the longer sides for the low-band. The shorted L-shaped strips are introduced to produce additional radiation resonance in the lower band to enhance the bandwidth. The crossed strip is used to excite two orthogonal polarizations with improved isolation. The dual-band antenna features of compact size with a dimension of only 0.376λ<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">_l</i> × 0.376λ<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">_l</i> × 0.1λ<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">_l</i> at 23.5 GHz. Furthermore, a 2 × 2 array is prototyped and verified. The results show that the antenna can achieve a lower band from 23.5 GHz to 30.8 GHz [fractional bandwidth (FBW) = 26.9%] and a higher band from 36.7 GHz to 47.3 GHz (FBW = 25.2%) for both polarizations. The proposed antenna and array could be promising candidates for 5G millimeter-wave applications.