In this paper, we propose a computer-aided design (CAD) tool in the electronic design automation (EDA) domain. This tool is dedicated for the design and simulation of Radiofrequency (RF) filters that are integrated into Advanced Design System (ADS) software. It includes a graphical user interface (GUI) developed using the design kit feature available under ADS and “Application Extension Language (AEL)” as a programming language. This will extend the existing smart filter design tool under ADS by adding more types of RF filters. The proposed feature will provide to users a rapid and an accurate tool to design and simulate RF filters by presenting interactive menus facilitating the process. As a proof of concept, an application of this tool is presented for the design of a Dual-Behavior Resonators filter. The tool can be upgraded by adding other RF components and even entire front-end circuits. In a future step, this tool will be enhanced by adding tuning capabilities to RF filters using ideal capacitors and varactors, which will make it the first one of its kind in the literature.