Compact cross-coupled filter with multilayer configuration for suppression of spurious responses

In this paper, a novel multilayer structure resonator is presented. Due to 3D geometrical configuration, the enhanced inner coupling is achieved easily. It is not only sharply reduced the size of filter but also obtained high spurious suppression. A fourth-order cross-coupled filter base on proposed topology is fabricated and measured. Two transmission zeros distributed in low and upper stopband respectively. Measured results show the characteristics of small size, good stopband performance and high suppression of spurious responses.