In order to develop suitable antenna configurations for mmWave band, the selection of the substrate material and the stack-up are also a quite indispensable topic that affects antenna characteristics and the workability. This study focuses on the design in different antenna in packages (AiPs), using different dielectric materials and comparing the differences in antenna characteristics, including antenna gain, bandwidth and radiated efficiency by simulation. Two stack-ups are determined in this study. The first stack-up is made of 4 layers metal and single type substrate of MGC970 series which is the currently prevailing material in the designs of the 5G AiPs. The second stack-up is the hybrid stack-up that composed of MGC970 series and PTFE (Polytetrafluoroethene) which is appropriate material to antenna design because of the low dielectric constant and a very low loss tangent.