28/38-GHz dual-band millimeter wave SIW array antenna with EBG structures for 5G applications

The design of linearly polarized dual-band substrate integrated waveguide (SIW) antenna/array operating at Ka-band is proposed. The single antenna element consists of a SIW cavity with two longitudinal slots engraved in one of the conducting planes. The longer and shorter slots are resonating at 28 GHz and 38 GHz, respectively. Only the simulated results are presented. All simulations have been carried out using industry-standard software, CST Microwave Studio. For single antenna element, an impedance bandwidth (S₁₁ <; -10 dB) of 0.45 GHz (1.60 %) and 2.20 GHz (5.8 %) is achieved with the maximum gain of 5.2 dBi and 5.9 dBi at 28 GHz and 38 GHz, respectively. To achieve high gain, a horizontally polarized linear array of four elements (1 × 4) is designed. For the antenna array, a microstrip lines feed network is designed using 3-dB wilkinson power divider. At 28 GHz and 38 GHz, the impedance bandwidth is 0.32 GHz (1.14 %) and 1.9 GHz (5%) having maximum gain of 11.9 dBi and 11.2 dBi, respectively. A low loss/cost substrate, RT/Duroid 5880 is used in the proposed designs.