A Low-Cost, High-Gain, Dual-Band Dual-Polarized Antenna Using Parasitic Patches Based on SISL for 5G Base Station Applications

A low-cost high-gain dual-band dual-polarized antenna is proposed based on substrate integrated suspended line (SISL) for 5G applications. The antenna mainly consists of driven patch etched with <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">π</i> slots, stacked patch, and parasitic patches. Based on the fundamental mode of the driven patch, the resonant points generated by the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">π</i> slots and the stacked patch respectively constitute the two operating bands of the antenna. The addition of four parasitic patches greatly improve the in-band gain and the gain stability of the antenna, and also generate a radiation null between the two operating bands, which improves the out-of-band suppression level of the antenna. The measured results show that the antenna covers 3.29–3.42 GHz (sub-band of 5G NR n78) and 4.73–5.32 GHz (extended beyond n79), with maximum gains of 9.96 dBi and 11.48 dBi, respectively. In addition, the proposed antenna is based on the FR4 substrate layers, which has the advantage of low cost. The isolation degree between the two polarization modes is greater than 35 dB.