## 5 Conclusions  
In this study, we designed and fabricated three pairs of nests made by adding elliptical patches to the fins of a novel UWB antipodal Vivaldi antenna suitable for breast cancer detection via microwave imaging. The small, compact size of the designed antenna enables the created system to be integrated into the circuit for the breast cancer detection prototype. For the performance testing of the proposed imaging system, an imaging system was created in the CST MWS simulation program. A very small spherical tumor with a diameter of 0.9 mm was placed into the heterogeneous breast model created in the simulation program and the image of the tumor's location was determined in the correct location. After the success achieved in the simulation application, the microwave breast cancer detection system was established for experimental measurement. For this purpose, we produced an opposite-polarity Vivaldi antenna, with homogeneous and heterogeneous breast phantoms. We left spherical tumors with a diameter of 16 mm inside the breast phantoms produced in the experimental environment. A scanner produced using a 3D printer was then used to measure the breast phantoms. The detection of the tumor in the homogeneous and heterogeneous phantoms was successfully observed with the designed RMWBI method. In the experimental setting, the tumor detection capacity depends significantly on the dynamic range of the VNA device used. Therefore, the tumor detection capacity is not as high as in the simulation setting. In the experimental setting, it is difficult to detect tumors in phantoms containing glandular tissue. This tissue weakens the tumor response. The dynamic range of the VNA device used allowed us to image a tumor with a diameter \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Ref. No.** & \
\begin{tabular}{c} **Simulation Study** \\ **(Tumor Diameter)** \\ \end{tabular} & **Breast Model** &
\begin{tabular}{c} **Experimental Study** \\ **(Tumor Diameter)** \\ \end{tabular} & **Breast Model** \\ \hline
[40] & 5 & Heterogeneous & - & - \\
[48] & 10 & Heterogeneous & 30 & Heterogeneous \\
[50] & - & - & 20 & Heterogeneous \\
[52] & 1.8 & Heterogeneous & - & - \\
[53] & 2 & Heterogeneous & 20 & Homogeneous \\
[73] & - & - & 25 & Heterogeneous \\
[75] & 6.5 & Heterogeneous & - & - \\
[76] & 5 & Heterogeneous & - & - \\
[77] & - & - & 25 & Homogeneous \\
[78] & 10 & Heterogeneous & - & - \\
[90] & 10 & Heterogeneous & - & - \\
[98] & 8 & Heterogeneous & - & - \\
[99] & 10 & Heterogeneous & - & - \\
[100] & 5 & Heterogeneous & - & - \\
[74] & 5 & Heterogeneous & 40 & Heterogeneous \\
[101] & 3 & Heterogeneous & - & - \\
[102] & 6 & Heterogeneous & - & - \\
[103] & 10 & Heterogeneous & - & - \\
[104] & 5 & Heterogeneous & - & - \\
[105] & 5 & Heterogeneous & - & - \\ Proposed & 0.9 & Heterogeneous & 16 & Heterogeneous \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Tumor detection studies in the literature (tumor size—simulation and experimental setting). of 16 mm. Thus, the 16 mm diameter tumor was detected in the correct location in the reconstructed images. The results obtained in our study show that the proposed antenna can be used for radar-based microwave breast cancer detection applications of the imaging system. The proposed system is a good candidate for future clinical studies and is a low-cost system. Conceptualization, S.Y. and M.B.K. ; methodology, S.Y. and M.B.K. ; validation, S.Y. and M.B.K. ; formal analysis, S.Y. and M.B.K. ; investigation, S.Y. and M.B.K. ; resources, S.Y. ; data curation, S.Y. ; writing--original draft preparation, S.Y. ; writing--review & editing, S.Y. and M.B.K. ; visualization, S.Y. ; consultancy, M.B.K. All authors have read and agreed to the published version of the manuscript. This research received no external funding. Not applicable. The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.