Modeling a 4-port Microwave-Based Biosensor for 3D Models Mapping hindering a comprehensive understanding of complex biological systems. This paper therefore introduces a four-port sensor configuration aiming to analyze a 3D entity, while considering not only its global dielectric response but also focusing on specific parts of this entity. The first stage toward the mapping of such a 3D and complex structure consists to consider it as divided in four parts. It implies developing an electrical model tailored specifically for the 4-port microwave-based biosensor. The architecture for the 4-port biosensor as well as the microfluidic part is illustrated in section II. The next section is then dedicated to the electrical model specifically developed for such a structure. To validate this electrical model, a mathematical verification is then performed. Finally, preliminary experiments with different concentrations of ethanol are evaluated in section IV.