The dielectric parameters help in understanding the structural, compositional and functional analysis of biological samples. These parameters have also been widely adopted in biomedical and therapeutic fields. In the microwave region, these parameters carry much interest because the principal constituent of most biological cells is water. Therefore, it is difficult to isolate the dielectric response of water present in a biological-composite. So, the technique with enhanced sensitivity is essential for measuring the dielectric properties of biological samples. In this paper, we report the design and CST simulation of a 2D-planar patch type antenna with capacitive coupling introduced by dividing the patch through a gap. The aforementioned design further improves the antenna’s sensitivity towards the dielectric properties of materials. Here, we simulated ten biological phantoms by measuring the shift in resonant frequency and return loss. Our results were identical when loading samples on either of the two introduced patches. These results suggest the repeatability and further improvements in a cavity-based technique where the sample localization is an important issue. Moreover, we analytically studied the dependency of gain and directivity of the antenna on the capacitive coupling, which plays a major role in the antenna’s sensitivity towards dielectric characterization.