Multifunctional Filtering Circuits: 3D Multifunctional Filtering Circuits Based on High-Q Dielectric Resonators and Coaxial Resonators

The rapid development of wireless technologies has created high demand for microwave circuits with compact size, low loss, and high efficiency. Bandpass filters (BPFs) are essential in wireless systems, which are cascaded with many circuits in RF front ends, i.e., power dividers [1], couplers [2], switches [3], and power amplifiers (PAs) [4]. They can be codesigned as multifunctional filtering circuits, including passive and active circuits, to reduce the loss and size of the whole system.