A survey of microstrip-based diplexer and triplexer filters: design methods and their performances

Microstrip-based diplexer (DiX), triplexer (TiX), quadplexer (QuX), and multiplexer (MuX) filters/antennas play a crucial role in wireless communication, enabling simultaneous transmission and reception of multiple frequency bands with minimal interference. This survey provides a comprehensive overview of the design methods and performance associated with these essential components. The manuscript begins by introducing the fundamental principles of microstrip filters, DiX and TiX. It then discusses the various design used to create these filters. The focus is on recent advancements, such as compact and multiband designs, as well as their integration with other components. We discuss performance metrics for evaluating microstrip-based DiX and TiX filters, covering key parameters such as size, insertion loss, isolation, operating band, and applications. The manuscript also explores and tabulates the trade-offs between different performance metrics and design considerations to meet specific application requirements. These include using advanced materials, metamaterials, and reconfigurable techniques to make the design more flexible and improve performance. Overall, this survey serves as a valuable resource for researchers, engineers, and practitioners in the field of microwave and RF engineering, providing insights into the state-of-the-art design methods and performance evaluation techniques for microstrip-based DiX and TiX filters.