Microwave and Millimeter-Wave Multifunction Filtering Circuits Using Three-Dimensional High-Integration Technology

Three-dimensional (3D) high-integration technologies, such as GaAs, CMOS, GaN, and MEMS, enhance the performance and functionality of passive circuits by significantly reducing size and minimizing parasitic effects, especially in millimeter-wave systems. This discussion explores theoretical methods and process implementations of high-performance multifunctional millimeter-wave filtering circuits using 3D integration. It focuses on lumped-distributed filters with GaAs-based IPD, MEMS-based bulk acoustic wave filters, and GaN filtering switches. These designs offer efficient solutions for implementing high-integration passive networks in wireless communication systems and related applications.