This work focuses on the design and measurement of the distortion impact of an Ultra-wide-band radar antenna. The low-pass prototype with equal parts was used as the model. The model is capable of minimizing the insertion-loss while also delivering the required stopband attenuation. The network model was constructed based on the low-pass prototype model, using the theory of coupled cavity resonator. The construction of narrow-band filters relied on the coupling coefficients between resonators and the external Q factors at the two terminal resonators, which served as fundamental parameters. The microwave implementation included the utilization of λ/4 inductive coupled TEM-mode coaxial resonators. The suggested filter exhibits characteristics of being small, stable, readily manufacturable, and cost-effective.